Repository: flutter
Issue: CustomScrollview layout sequence throws when using 'center' property with 'CupertinoSliverRefreshControl' inside the slivers.
Labels: c: crash,framework,f: scrolling,f: cupertino,d: api docs,has reproducible steps,P2,found in release: 3.0,found in release: 3.1,team-design,triaged-design

## Steps to Reproduce

<!-- You must include full steps to reproduce so that we can reproduce the problem. -->

1. Create CustomScrollview
2. use center: _globalKey and in slivers: [.... , SliverPersistentHeader(key: _globalKey,....) ]  to center this header
3. put CupertinoSliverRefreshControl(...) in slivers: []
4. exception is thrown when navigate to this page

**Expected results:** <!-- what did you want to see? -->

**Actual results:** <!-- what did you see? -->

<details>
  <summary>Logs</summary>

<!--
      Run your application with `flutter run --verbose` and attach all the
      log output below between the lines with the backticks. If there is an
      exception, please see if the error message includes enough information
      to explain how to solve the issue.
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## Stacktrace
```
E/flutter ( 3684): [ERROR:flutter/shell/common/shell.cc(242)] Dart Unhandled Exception: Null check operator used on a null value, stack trace: #0      RenderViewportBase.layoutChildSequence (package:flutter/src/rendering/viewport.dart:527:64)
E/flutter ( 3684): #1      RenderViewport._attemptLayout (package:flutter/src/rendering/viewport.dart:1552:29)
E/flutter ( 3684): #2      RenderViewport.performLayout (package:flutter/src/rendering/viewport.dart:1479:20)
E/flutter ( 3684): #3      RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #4      RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #5      RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #6      RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #7      RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #8      RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #9      RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #10     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #11     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #12     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #13     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #14     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #15     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #16     ChildLayoutHelper.layoutChild (package:flutter/src/rendering/layout_helper.dart:54:11)
E/flutter ( 3684): #17     RenderStack._computeSize (package:flutter/src/rendering/stack.dart:570:43)
E/flutter ( 3684): #18     RenderStack.performLayout (package:flutter/src/rendering/stack.dart:597:12)
E/flutter ( 3684): #19     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #20     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #21     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #22     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #23     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #24     RenderPadding.performLayout (package:flutter/src/rendering/shifted_box.dart:226:12)
E/flutter ( 3684): #25     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #26     ChildLayoutHelper.layoutChild (package:flutter/src/rendering/layout_helper.dart:54:11)
E/flutter ( 3684): #27     RenderStack._computeSize (package:flutter/src/rendering/stack.dart:570:43)
E/flutter ( 3684): #28     RenderStack.performLayout (package:flutter/src/rendering/stack.dart:597:12)
E/flutter ( 3684): #29     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #30     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #31     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #32     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #33     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #34     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #35     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #36     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #37     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #38     ChildLayoutHelper.layoutChild (package:flutter/src/rendering/layout_helper.dart:54:11)
E/flutter ( 3684): #39     RenderStack._computeSize (package:flutter/src/rendering/stack.dart:570:43)
E/flutter ( 3684): #40     RenderStack.performLayout (package:flutter/src/rendering/stack.dart:597:12)
E/flutter ( 3684): #41     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #42     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #43     RenderObject.layout (package:flutter/src/rendering/object.dart:1784:7)
E/flutter ( 3684): #44     RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:118:14)
E/flutter ( 3684): #45    
```

<!--
     Run `flutter analyze` and attach any output of that command below.
     If there are any analysis errors, try resolving them before filing this issue.
-->
## flutter analyze
```

Analyzing ulu_platform_demo...                                          

   info • Unused import: 'package:provider/provider.dart' • lib/backend/data_provider.dart:2:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/helper/api_helper.dart' • lib/backend/data_provider.dart:3:8 • unused_import
   info • 'FlatButton' is deprecated and shouldn't be used. Use TextButton instead. See the migration guide in flutter.dev/go/material-button-migration-guide). This feature was deprecated after v1.25.0-8.1.pre. • lib/game_detail_widgets/upvote_number.dart:14:12 •
          deprecated_member_use
   info • Unused import: 'dart:math' • lib/helper/api_helper.dart:6:8 • unused_import
   info • Unused import: 'dart:typed_data' • lib/helper/api_helper.dart:7:8 • unused_import
   info • Unused import: 'package:flutter/cupertino.dart' • lib/helper/api_helper.dart:8:8 • unused_import
   info • Unused import: 'package:flutter/foundation.dart' • lib/helper/api_helper.dart:9:8 • unused_import
   info • 'await' applied to 'MultipartFile', which is not a 'Future' • lib/helper/api_helper.dart:89:21 • await_only_futures
   info • The value of the local variable 'concat' isn't used • lib/helper/api_helper.dart:202:9 • unused_local_variable
   info • Unused import: 'package:flutter/foundation.dart' • lib/lang/index.dart:4:8 • unused_import
   info • Unused import: 'package:dokit/dokit.dart' • lib/main.dart:1:8 • unused_import
   info • Avoid using braces in interpolation when not needed • lib/main.dart:61:46 • unnecessary_brace_in_string_interps
   info • The value of the field '_error' isn't used • lib/main.dart:104:8 • unused_field
   info • This function has a return type of 'Route<dynamic>', but doesn't end with a return statement • lib/main.dart:289:18 • missing_return
   info • Equality operator `==` invocation with references of unrelated types • lib/main.dart:439:22 • unrelated_type_equality_checks
   info • Equality operator `==` invocation with references of unrelated types • lib/main.dart:453:22 • unrelated_type_equality_checks
   info • Equality operator `==` invocation with references of unrelated types • lib/main.dart:467:22 • unrelated_type_equality_checks
   info • The value of the local variable 'controller' isn't used • lib/main.dart:476:15 • unused_local_variable
   info • The value of the local variable 'isUserCenter' isn't used • lib/main.dart:479:16 • unused_local_variable
   info • Equality operator `==` invocation with references of unrelated types • lib/main.dart:485:19 • unrelated_type_equality_checks
   info • This function has a return type of 'Widget', but doesn't end with a return statement • lib/main.dart:600:10 • missing_return
   info • This function has a return type of 'Route<dynamic>', but doesn't end with a return statement • lib/main.dart:633:18 • missing_return
   info • Avoid using braces in interpolation when not needed • lib/main.dart:634:58 • unnecessary_brace_in_string_interps
   info • The value of the local variable 'user' isn't used • lib/main.dart:635:11 • unused_local_variable
   info • Unused import: 'package:ulu_platform_demo/page_gift/gift.dart' • lib/model/model_class.dart:7:8 • unused_import
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:425:22 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:425:45 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:474:25 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:474:55 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:532:13 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:532:30 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:532:47 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:532:64 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:532:84 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:532:109 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:562:19 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/model/model_class.dart:562:41 • unnecessary_brace_in_string_interps
   info • Unused import: 'package:ulu_platform_demo/lang/index.dart' • lib/model/platform_info.dart:8:8 • unused_import
   info • Avoid wrapping fields in getters and setters just to be "safe" • lib/model/platform_info.dart:12:14 • unnecessary_getters_setters
   info • Avoid wrapping fields in getters and setters just to be "safe" • lib/model/platform_info.dart:14:14 • unnecessary_getters_setters
   info • Unused import: 'package:ulu_platform_demo/model/model_class.dart' • lib/page_games/download/download_button.dart:4:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: DownloadButton.packageName, DownloadButton.downloadUrl, DownloadButton.isGreyBackground, DownloadButton.downloadTitle •
          lib/page_games/download/download_button.dart:11:7 • must_be_immutable
   info • The value of the local variable 'isResume' isn't used • lib/page_games/download/download_button.dart:82:10 • unused_local_variable
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:24:78 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:24:105 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:24:139 • unnecessary_brace_in_string_interps
   info • The value of the field '_timer' isn't used • lib/page_games/download/download_provider.dart:28:9 • unused_field
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:74:32 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:74:42 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:79:51 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:83:44 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:128:66 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:180:18 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:205:36 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:215:36 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_games/download/download_provider.dart:237:36 • unnecessary_brace_in_string_interps
   info • Unused import: 'package:meta/meta.dart' • lib/page_games/download_status.dart:3:8 • unused_import
   info • Unused import: 'package:cached_network_image/cached_network_image.dart' • lib/page_games/fullscreen_image.dart:2:8 • unused_import
   info • Unused import: '../model/model_class.dart' • lib/page_games/fullscreen_image.dart:7:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: FullscreenImage.initial • lib/page_games/fullscreen_image.dart:10:7 • must_be_immutable
   info • The value of the field '_resize' isn't used • lib/page_games/fullscreen_image.dart:29:10 • unused_field
   info • Avoid using braces in interpolation when not needed • lib/page_games/fullscreen_image.dart:66:37 • unnecessary_brace_in_string_interps
   info • Unused import: 'dart:ui' • lib/page_games/game_api_provider.dart:4:8 • unused_import
   info • Unused import: 'dart:convert' • lib/page_games/game_detail.dart:1:8 • unused_import
   info • Unused import: 'dart:ffi' • lib/page_games/game_detail.dart:2:8 • unused_import
   info • Unused import: 'package:flutter/services.dart' • lib/page_games/game_detail.dart:9:8 • unused_import
   info • Unused import: 'package:http/http.dart' • lib/page_games/game_detail.dart:12:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/model/platform_info.dart' • lib/page_games/game_detail.dart:16:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_games/video_player.dart' • lib/page_games/game_detail.dart:19:8 • unused_import
   info • Unused import: 'package:url_launcher/url_launcher.dart' • lib/page_games/game_detail.dart:23:8 • unused_import
   info • Unused import: 'package:flushbar/flushbar.dart' • lib/page_games/game_detail.dart:26:8 • unused_import
   info • Unused import: 'package:webview_flutter/webview_flutter.dart' • lib/page_games/game_detail.dart:31:8 • unused_import
   info • Unused import: 'game_jump.dart' • lib/page_games/game_detail.dart:33:8 • unused_import
   info • The value of the field '_controller' isn't used • lib/page_games/game_detail.dart:67:27 • unused_field
   info • The value of the field '_hasVideo' isn't used • lib/page_games/game_detail.dart:68:8 • unused_field
   info • The value of the local variable 'task' isn't used • lib/page_games/game_detail.dart:112:17 • unused_local_variable
   info • The receiver uses '?.', so its value can be null • lib/page_games/game_detail.dart:115:40 • can_be_null_after_null_aware
   info • 'RaisedButton' is deprecated and shouldn't be used. Use ElevatedButton instead. See the migration guide in flutter.dev/go/material-button-migration-guide). This feature was deprecated after v1.25.0-8.1.pre. • lib/page_games/game_detail.dart:314:19 •
          deprecated_member_use
   info • Unused import: 'package:flutter/material.dart' • lib/page_games/game_jump.dart:3:8 • unused_import
   info • Avoid using braces in interpolation when not needed • lib/page_games/game_jump.dart:51:74 • unnecessary_brace_in_string_interps
   info • Unused import: 'package:flushbar/flushbar.dart' • lib/page_games/games_list_tab.dart:3:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/helper/appexceptions.dart' • lib/page_games/games_list_tab.dart:10:8 • unused_import
   info • Unused import: 'game_jump.dart' • lib/page_games/games_list_tab.dart:28:8 • unused_import
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_games/games_list_tab.dart:60:32 • deprecated_member_use
   info • 'await' applied to 'void', which is not a 'Future' • lib/page_games/games_list_tab.dart:80:5 • await_only_futures
   info • The receiver uses '?.', so its value can be null • lib/page_games/games_list_tab.dart:91:25 • can_be_null_after_null_aware
   info • The value of the local variable 'lc' isn't used • lib/page_games/games_list_tab.dart:102:11 • unused_local_variable
   info • Avoid using braces in interpolation when not needed • lib/page_games/games_list_tab.dart:149:54 • unnecessary_brace_in_string_interps
   info • 'FlatButton' is deprecated and shouldn't be used. Use TextButton instead. See the migration guide in flutter.dev/go/material-button-migration-guide). This feature was deprecated after v1.25.0-8.1.pre. • lib/page_games/games_list_tab.dart:205:27 •
          deprecated_member_use
   info • The declaration '_buildRecommendedGames' isn't referenced • lib/page_games/games_list_tab.dart:280:16 • unused_element
   info • The receiver uses '?.', so its value can be null • lib/page_games/games_list_tab.dart:353:36 • can_be_null_after_null_aware
   info • Unused import: 'dart:math' • lib/page_games/video_player.dart:5:8 • unused_import
   info • Avoid using unnecessary statements • lib/page_games/video_player.dart:23:9 • unnecessary_statements
   info • Unused import: 'package:http/http.dart' • lib/page_gift/gift.dart:3:8 • unused_import
   info • Unused import: 'package:pull_to_refresh/pull_to_refresh.dart' • lib/page_gift/gift.dart:4:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/backend/data_provider.dart' • lib/page_gift/gift.dart:5:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/helper/api_helper.dart' • lib/page_gift/gift.dart:6:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/helper/appexceptions.dart' • lib/page_gift/gift.dart:7:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/model/platform_info.dart' • lib/page_gift/gift.dart:9:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/gift_api.dart' • lib/page_gift/gift.dart:10:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/gift_provider.dart' • lib/page_gift/gift.dart:11:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/received_gift.dart' • lib/page_gift/gift.dart:12:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/user_center.dart' • lib/page_gift/gift.dart:13:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/user_controller.dart' • lib/page_gift/gift.dart:14:8 • unused_import
   info • The name AppLocalizationsDelegate is shown, but isn’t used • lib/page_gift/gift.dart:17:28 • unused_shown_name
   info • Unused import: 'package:ulu_platform_demo/widgets/list_item.dart' • lib/page_gift/gift.dart:19:8 • unused_import
   info • Duplicate import • lib/page_gift/gift.dart:21:8 • duplicate_import
   info • Unused import: 'gift_detail.dart' • lib/page_gift/gift.dart:23:8 • unused_import
   info • Avoid using braces in interpolation when not needed • lib/page_gift/gift_api.dart:53:78 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_gift/gift_api.dart:53:94 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_gift/gift_api.dart:69:53 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_gift/gift_api.dart:69:69 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_gift/gift_api.dart:88:73 • unnecessary_brace_in_string_interps
   info • Unused import: 'package:flutter/scheduler.dart' • lib/page_gift/gift_detail.dart:4:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/backend/data_provider.dart' • lib/page_gift/gift_detail.dart:6:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/gift.dart' • lib/page_gift/gift_detail.dart:12:8 • unused_import
   info • The value of the local variable 'lc' isn't used • lib/page_gift/gift_detail.dart:49:11 • unused_local_variable
   info • The value of the local variable 'user' isn't used • lib/page_gift/gift_detail.dart:116:9 • unused_local_variable
   info • The value of the local variable 'loc' isn't used • lib/page_gift/gift_detail.dart:117:9 • unused_local_variable
   info • Unused import: 'package:flushbar/flushbar.dart' • lib/page_gift/gift_list_item.dart:1:8 • unused_import
   info • Unused import: 'package:fluttertoast/fluttertoast.dart' • lib/page_gift/gift_list_item.dart:5:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/helper/api_helper.dart' • lib/page_gift/gift_list_item.dart:6:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/helper/appexceptions.dart' • lib/page_gift/gift_list_item.dart:7:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/main.dart' • lib/page_gift/gift_list_item.dart:8:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/model/platform_info.dart' • lib/page_gift/gift_list_item.dart:10:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/gift_provider.dart' • lib/page_gift/gift_list_item.dart:13:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/select_server_role.dart' • lib/page_gift/gift_list_item.dart:14:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/widgets/toast_template.dart' • lib/page_gift/gift_list_item.dart:19:8 • unused_import
   info • Unused import: '../place_holder_img.dart' • lib/page_gift/gift_list_item.dart:20:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/widgets/rich_text_widget.dart' • lib/page_gift/gift_list_item.dart:23:8 • unused_import
   info • Unused import: 'package:provider/provider.dart' • lib/page_gift/gift_list_provider.dart:5:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/model/platform_info.dart' • lib/page_gift/gift_list_provider.dart:6:8 • unused_import
   info • Unused import: '../user_controller.dart' • lib/page_gift/gift_list_provider.dart:8:8 • unused_import
   info • Avoid using braces in interpolation when not needed • lib/page_gift/num_in_span_text.dart:18:31 • unnecessary_brace_in_string_interps
   info • Unused import: 'package:ulu_platform_demo/model/platform_info.dart' • lib/page_gift/received_gift.dart:9:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/gift_list_item.dart' • lib/page_gift/received_gift.dart:10:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/gift_provider.dart' • lib/page_gift/received_gift.dart:12:8 • unused_import
   info • The value of the local variable 'user' isn't used • lib/page_gift/received_gift.dart:28:11 • unused_local_variable
   info • Avoid using braces in interpolation when not needed • lib/page_gift/received_gift.dart:126:82 • unnecessary_brace_in_string_interps
   info • Unused import: 'dart:io' • lib/page_gift/server_role_popup.dart:3:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_games/game_jump.dart' • lib/page_gift/server_role_popup.dart:13:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/gift_provider.dart' • lib/page_gift/server_role_popup.dart:15:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_gift/store_open.dart' • lib/page_gift/server_role_popup.dart:18:8 • unused_import
   info • Unused import: 'package:url_launcher/url_launcher.dart' • lib/page_gift/server_role_popup.dart:22:8 • unused_import
   info • The value of the field '_timer' isn't used • lib/page_gift/server_role_popup.dart:48:9 • unused_field
   info • Avoid using braces in interpolation when not needed • lib/page_gift/server_role_popup.dart:55:12 • unnecessary_brace_in_string_interps
   info • The value of the local variable 'jump' isn't used • lib/page_gift/server_role_popup.dart:272:24 • unused_local_variable
   info • The value of the local variable 'timeIsUp' isn't used • lib/page_gift/server_role_popup.dart:273:10 • unused_local_variable
   info • The value of the local variable 'errMsg' isn't used • lib/page_gift/server_role_popup.dart:333:14 • unused_local_variable
   info • Unused import: 'package:ulu_platform_demo/page_infos/widgets/comment_item.dart' • lib/page_infos/backend/story_api.dart:8:8 • unused_import
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:35:54 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:35:72 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:35:85 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:65:61 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:65:80 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:65:93 • unnecessary_brace_in_string_interps
   info • Name non-constant identifiers using lowerCamelCase • lib/page_infos/backend/story_api.dart:85:11 • non_constant_identifier_names
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:106:63 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:106:84 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:106:97 • unnecessary_brace_in_string_interps
   info • Name non-constant identifiers using lowerCamelCase • lib/page_infos/backend/story_api.dart:122:11 • non_constant_identifier_names
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:143:67 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:143:80 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:168:59 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:190:48 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:190:63 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:190:76 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:300:117 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/backend/story_api.dart:317:123 • unnecessary_brace_in_string_interps
   info • The getter doesn't override an inherited getter • lib/page_infos/backend/story_list_provider.dart:164:14 • override_on_non_overriding_member
   info • Unused import: 'package:provider/provider.dart' • lib/page_infos/backend/topic_list_provider.dart:9:8 • unused_import
   info • Unused import: '../../user_controller.dart' • lib/page_infos/backend/topic_list_provider.dart:10:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/widgets/back_button_custom.dart' • lib/page_infos/create_story.dart:9:8 • unused_import
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_infos/create_story.dart:30:40 • deprecated_member_use
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_infos/create_story.dart:31:33 • deprecated_member_use
   info • The value of the field '_error' isn't used • lib/page_infos/create_story.dart:32:10 • unused_field
   info • Unused import: 'package:flutter/scheduler.dart' • lib/page_infos/details/comment_detail.dart:5:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/main.dart' • lib/page_infos/details/comment_detail.dart:9:8 • unused_import
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_infos/details/comment_detail.dart:53:31 • deprecated_member_use
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_infos/details/comment_detail.dart:69:40 • deprecated_member_use
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_infos/details/comment_detail.dart:71:33 • deprecated_member_use
   info • The value of the field '_error' isn't used • lib/page_infos/details/comment_detail.dart:75:10 • unused_field
   info • The value of the field '_loading' isn't used • lib/page_infos/details/comment_detail.dart:81:8 • unused_field
   info • The value of the '?.' operator can be 'null', which isn't appropriate as an operand of a logical operator • lib/page_infos/details/comment_detail.dart:210:58 • null_aware_in_logical_operator
   info • Unused import: 'package:ulu_platform_demo/main.dart' • lib/page_infos/details/story_detail.dart:9:8 • unused_import
   info • The value of the field '_error' isn't used • lib/page_infos/details/story_detail.dart:74:10 • unused_field
   info • The value of the field '_refreshController' isn't used • lib/page_infos/details/story_detail.dart:84:21 • unused_field
   info • The value of the local variable 'provider' isn't used • lib/page_infos/details/story_detail.dart:111:11 • unused_local_variable
   info • The value of the '?.' operator can be 'null', which isn't appropriate as an operand of a logical operator • lib/page_infos/details/story_detail.dart:178:58 • null_aware_in_logical_operator
   info • Unused import: 'package:webview_flutter/webview_flutter.dart' • lib/page_infos/info_list_detail.dart:12:8 • unused_import
   info • 'FlatButton' is deprecated and shouldn't be used. Use TextButton instead. See the migration guide in flutter.dev/go/material-button-migration-guide). This feature was deprecated after v1.25.0-8.1.pre. • lib/page_infos/info_list_detail.dart:96:19 •
          deprecated_member_use
   info • Unused import: 'package:flutter/foundation.dart' • lib/page_infos/info_list_tab.dart:4:8 • unused_import
   info • Unused import: 'package:http/http.dart' • lib/page_infos/info_list_tab.dart:6:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/user_info.dart' • lib/page_infos/info_list_tab.dart:8:8 • unused_import
   info • Unused import: 'info_list_tab_1_news.dart' • lib/page_infos/info_list_tab.dart:10:8 • unused_import
   info • Unused import: 'info_list_tab_2_movies.dart' • lib/page_infos/info_list_tab.dart:11:8 • unused_import
   info • Unused import: '../model/model_class.dart' • lib/page_infos/info_list_tab.dart:12:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: InfoListTab.onChangeTab, InfoListTab._refreshController • lib/page_infos/info_list_tab.dart:18:7 • must_be_immutable
   info • The value of the field '_refreshController' isn't used • lib/page_infos/info_list_tab.dart:23:21 • unused_field
warning • The parameter 'onPressed' is required • lib/page_infos/info_list_tab.dart:32:25 • missing_required_param
   info • Unused import: 'package:ulu_platform_demo/model/platform_info.dart' • lib/page_infos/info_list_tab_1_news.dart:7:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_games/game_detail.dart' • lib/page_infos/info_list_tab_1_news.dart:8:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_infos/pagelogic.dart' • lib/page_infos/info_list_tab_1_news.dart:13:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_infos/info_list_detail.dart' • lib/page_infos/info_list_tab_1_news.dart:14:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/place_holder_img.dart' • lib/page_infos/info_list_tab_1_news.dart:18:8 • unused_import
   info • Unused import: '../page_infos/news_api_provider.dart' • lib/page_infos/info_list_tab_1_news.dart:23:8 • unused_import
   info • The name AppLocalizationsDelegate is shown, but isn’t used • lib/page_infos/info_list_tab_1_news.dart:25:28 • unused_shown_name
   info • Unused import: 'package:carousel_slider/carousel_slider.dart' • lib/page_infos/info_list_tab_1_news.dart:26:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: InfoTab1.onChangeTab • lib/page_infos/info_list_tab_1_news.dart:42:7 • must_be_immutable
   info • The value of the field '_current' isn't used • lib/page_infos/info_list_tab_1_news.dart:54:13 • unused_field
   info • This method overrides a method annotated as '@mustCallSuper' in 'AutomaticKeepAliveClientMixin', but doesn't invoke the overridden method • lib/page_infos/info_list_tab_1_news.dart:73:10 • must_call_super
   info • The value of the local variable 'lc' isn't used • lib/page_infos/info_list_tab_1_news.dart:74:9 • unused_local_variable
   info • The declaration '_onStoryDelete' isn't referenced • lib/page_infos/info_list_tab_1_news.dart:201:8 • unused_element
   info • The value of the local variable 'provider' isn't used • lib/page_infos/info_list_tab_1_news.dart:230:9 • unused_local_variable
   info • Unused import: 'package:ulu_platform_demo/helper/api_helper.dart' • lib/page_infos/info_list_tab_2_movies.dart:4:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_infos/news_api_provider.dart' • lib/page_infos/info_list_tab_2_movies.dart:6:8 • unused_import
   info • This function has a return type of 'FutureOr<List<NewsRecord>>', but doesn't end with a return statement • lib/page_infos/info_list_tab_2_movies.dart:52:28 • missing_return
   info • Unused import: 'package:ulu_platform_demo/page_games/game_api_provider.dart' • lib/page_infos/news_api_provider.dart:10:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/model/platform_info.dart' • lib/page_infos/pagelogic.dart:7:8 • unused_import
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_infos/pagelogic.dart:22:35 • deprecated_member_use
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_infos/pagelogic.dart:58:22 • deprecated_member_use
   info • Unused import: 'package:ulu_platform_demo/model/platform_info.dart' • lib/page_infos/select_circle_page.dart:6:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_infos/backend/story_api.dart' • lib/page_infos/select_circle_page.dart:7:8 • unused_import
   info • The value of the local variable 'locale' isn't used • lib/page_infos/select_circle_page.dart:36:9 • unused_local_variable
   info • Unused import: 'package:ulu_platform_demo/lang/index.dart' • lib/page_infos/widgets/custom_popup_button.dart:6:8 • unused_import
   info • Avoid using braces in interpolation when not needed • lib/page_infos/widgets/custom_popup_button.dart:43:35 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/widgets/custom_popup_button.dart:51:55 • unnecessary_brace_in_string_interps
   info • Unused import: 'package:flutter/cupertino.dart' • lib/page_infos/widgets/formated_creation_date.dart:3:8 • unused_import
   info • Avoid using braces in interpolation when not needed • lib/page_infos/widgets/formated_creation_date.dart:22:28 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_infos/widgets/formated_creation_date.dart:25:30 • unnecessary_brace_in_string_interps
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: MatrixImage.len • lib/page_infos/widgets/matrix_image.dart:11:7 • must_be_immutable
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: OverlayMenu.items • lib/page_infos/widgets/overlay_menu.dart:5:7 • must_be_immutable
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_infos/widgets/replys_text.dart:22:29 • deprecated_member_use
   info • Unused import: 'package:ulu_platform_demo/page_infos/backend/story_api.dart' • lib/page_infos/widgets/story.dart:9:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_infos/widgets/story_more_menu.dart' • lib/page_infos/widgets/story.dart:12:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/widgets/PopupMenuItemCustomPadding.dart' • lib/page_infos/widgets/story.dart:14:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/widgets/free_menubutton.dart' • lib/page_infos/widgets/story.dart:15:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/user_controller.dart' • lib/page_infos/widgets/thumbup_button.dart:6:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: BindPhone._child • lib/page_me/bind_phone.dart:9:7 • must_be_immutable
   info • The value of the field '_cachedUserInfo' isn't used • lib/page_me/binding_bloc.dart:22:7 • unused_field
   info • A value of type 'void' can't be returned by the 'onError' handler because it must be assignable to 'FutureOr<UserInfo>' • lib/page_me/binding_bloc.dart:37:35 • return_of_invalid_type_from_catch_error
   info • A value of type 'void' can't be returned by the 'onError' handler because it must be assignable to 'FutureOr<UserInfo>' • lib/page_me/binding_bloc.dart:54:35 • return_of_invalid_type_from_catch_error
   info • This function has a return type of 'FutureOr<FacebookAccessToken>', but doesn't end with a return statement • lib/page_me/binding_bloc.dart:58:31 • missing_return
   info • The value of the local variable 'token' isn't used • lib/page_me/binding_bloc.dart:66:35 • unused_local_variable
   info • Unused import: 'package:flushbar/flushbar.dart' • lib/page_me/bindings.dart:5:8 • unused_import
   info • The value of the local variable 'lc' isn't used • lib/page_me/bindings.dart:29:11 • unused_local_variable
   info • The value of the field '_currentInfo' isn't used • lib/page_me/bindings.dart:49:18 • unused_field
   info • The value of the local variable 'params' isn't used • lib/page_me/change_avatar.dart:85:11 • unused_local_variable
   info • The value of the local variable 'header' isn't used • lib/page_me/change_avatar.dart:87:11 • unused_local_variable
   info • This function has a return type of 'FutureOr<bool>', but doesn't end with a return statement • lib/page_me/change_avatar.dart:96:16 • missing_return
   info • 'await' applied to 'void', which is not a 'Future' • lib/page_me/change_avatar.dart:106:5 • await_only_futures
   info • 'FlatButton' is deprecated and shouldn't be used. Use TextButton instead. See the migration guide in flutter.dev/go/material-button-migration-guide). This feature was deprecated after v1.25.0-8.1.pre. • lib/page_me/change_avatar.dart:124:16 •
          deprecated_member_use
   info • 'FlatButton' is deprecated and shouldn't be used. Use TextButton instead. See the migration guide in flutter.dev/go/material-button-migration-guide). This feature was deprecated after v1.25.0-8.1.pre. • lib/page_me/change_avatar.dart:137:16 •
          deprecated_member_use
   info • Unused import: 'package:ulu_platform_demo/helper/api_helper.dart' • lib/page_me/crop_avatar.dart:5:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/widgets/back_button_custom.dart' • lib/page_me/crop_avatar.dart:11:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: CropAvatar.image • lib/page_me/crop_avatar.dart:14:7 • must_be_immutable
   info • The value of the local variable 'size' isn't used • lib/page_me/crop_avatar.dart:32:11 • unused_local_variable
   info • Unused import: 'package:country_code_picker/country_code_picker.dart' • lib/page_me/email_binding.dart:3:8 • unused_import
   info • Unused import: 'package:flushbar/flushbar.dart' • lib/page_me/email_binding.dart:4:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/model/model_class.dart' • lib/page_me/email_binding.dart:8:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: EmailBind._child • lib/page_me/email_binding.dart:15:7 • must_be_immutable
   info • Name non-constant identifiers using lowerCamelCase • lib/page_me/email_binding.dart:52:16 • non_constant_identifier_names
   info • Name non-constant identifiers using lowerCamelCase • lib/page_me/email_binding.dart:59:13 • non_constant_identifier_names
warning • The parameter 'onPressed' is required • lib/page_me/email_binding.dart:152:24 • missing_required_param
warning • The parameter 'onPressed' is required • lib/page_me/email_binding.dart:162:22 • missing_required_param
   info • Unused import: 'dart:async' • lib/page_me/email_login.dart:1:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/helper/appexceptions.dart' • lib/page_me/email_login.dart:5:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/email_register.dart' • lib/page_me/email_login.dart:6:8 • unused_import
   info • The value of the local variable 'controller' isn't used • lib/page_me/email_login.dart:37:9 • unused_local_variable
   info • 'FlatButton' is deprecated and shouldn't be used. Use TextButton instead. See the migration guide in flutter.dev/go/material-button-migration-guide). This feature was deprecated after v1.25.0-8.1.pre. • lib/page_me/email_login.dart:108:24 •
          deprecated_member_use
   info • Unused import: 'package:flushbar/flushbar.dart' • lib/page_me/email_register.dart:5:8 • unused_import
   info • Unused import: 'package:flutter/services.dart' • lib/page_me/email_register.dart:9:8 • unused_import
   info • Unused import: 'package:url_launcher/url_launcher.dart' • lib/page_me/email_register.dart:20:8 • unused_import
   info • Unused import: 'package:flushbar/flushbar.dart' • lib/page_me/forget_password.dart:5:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: ForgetPasswordOuter._authCode • lib/page_me/forget_password.dart:17:7 • must_be_immutable
   info • Name non-constant identifiers using lowerCamelCase • lib/page_me/forget_password.dart:145:3 • non_constant_identifier_names
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: LoginContent._editingController • lib/page_me/login_refactor/login_page.dart:10:7 • must_be_immutable
   info • Unused import: 'package:ulu_platform_demo/page_me/user_info.dart' • lib/page_me/more_page_from_mypagetab.dart:9:8 • unused_import
   info • Unused import: 'package:provider/provider.dart' • lib/page_me/my_business_logic.dart:16:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/lang/index.dart' • lib/page_me/my_business_logic.dart:17:8 • unused_import
   info • Close instances of `dart.core.Sink` • lib/page_me/my_business_logic.dart:40:23 • close_sinks
   info • Close instances of `dart.core.Sink` • lib/page_me/my_business_logic.dart:43:34 • close_sinks
   info • Close instances of `dart.core.Sink` • lib/page_me/my_business_logic.dart:46:26 • close_sinks
   info • Close instances of `dart.core.Sink` • lib/page_me/my_business_logic.dart:49:26 • close_sinks
   info • Close instances of `dart.core.Sink` • lib/page_me/my_business_logic.dart:53:20 • close_sinks
   info • Close instances of `dart.core.Sink` • lib/page_me/my_business_logic.dart:56:28 • close_sinks
   info • Close instances of `dart.core.Sink` • lib/page_me/my_business_logic.dart:59:28 • close_sinks
   info • Close instances of `dart.core.Sink` • lib/page_me/my_business_logic.dart:62:28 • close_sinks
   info • Close instances of `dart.core.Sink` • lib/page_me/my_business_logic.dart:75:9 • close_sinks
   info • The value of the field '_controller' isn't used • lib/page_me/my_business_logic.dart:75:9 • unused_field
   info • This function has a return type of 'FutureOr<User>', but doesn't end with a return statement • lib/page_me/my_business_logic.dart:120:16 • missing_return
   info • This function has a return type of 'FutureOr<FacebookAccessToken>', but doesn't end with a return statement • lib/page_me/my_business_logic.dart:138:31 • missing_return
   info • The value of the local variable 'token' isn't used • lib/page_me/my_business_logic.dart:147:35 • unused_local_variable
   info • This function has a return type of 'FutureOr<GoogleSignInAccount>', but doesn't end with a return statement • lib/page_me/my_business_logic.dart:177:31 • missing_return
   info • This function has a return type of 'FutureOr<int>', but doesn't end with a return statement • lib/page_me/my_business_logic.dart:196:15 • missing_return
   info • Unused import: 'package:flutter/scheduler.dart' • lib/page_me/my_page_tab.dart:8:8 • unused_import
   info • Unused import: 'package:package_info/package_info.dart' • lib/page_me/my_page_tab.dart:9:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/helper/appexceptions.dart' • lib/page_me/my_page_tab.dart:11:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/main.dart' • lib/page_me/my_page_tab.dart:12:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/bindings.dart' • lib/page_me/my_page_tab.dart:18:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/security_page.dart' • lib/page_me/my_page_tab.dart:20:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/setting.dart' • lib/page_me/my_page_tab.dart:21:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/widgets/list_content_widget.dart' • lib/page_me/my_page_tab.dart:25:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/widgets/navigation_bar.dart' • lib/page_me/my_page_tab.dart:26:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/widgets/static_tablecell.dart' • lib/page_me/my_page_tab.dart:27:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: MyPageTab.added • lib/page_me/my_page_tab.dart:41:7 • must_be_immutable
   info • The value of the local variable 'lc' isn't used • lib/page_me/my_page_tab.dart:51:11 • unused_local_variable
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: MyPage.alreadyShowedLogin • lib/page_me/my_page_tab.dart:56:7 • must_be_immutable
   info • 'List' is deprecated and shouldn't be used. Use a list literal, [], or the List.filled constructor instead • lib/page_me/my_page_tab.dart:68:28 • deprecated_member_use
   info • The value of the local variable 'controller' isn't used • lib/page_me/my_page_tab.dart:119:11 • unused_local_variable
   info • The value of the local variable 'myBusinessLogic' isn't used • lib/page_me/my_page_tab.dart:125:11 • unused_local_variable
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: _SliverAppBarTitle.username • lib/page_me/my_page_tab.dart:519:7 • must_be_immutable
   info • Unused import: 'dart:async' • lib/page_me/password_reset.dart:3:8 • unused_import
   info • Unused import: 'package:flushbar/flushbar.dart' • lib/page_me/password_reset.dart:5:8 • unused_import
   info • Unused import: 'package:flutter/services.dart' • lib/page_me/password_reset.dart:8:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/email_binding.dart' • lib/page_me/password_reset.dart:10:8 • unused_import
   info • Close instances of `dart.core.Sink` • lib/page_me/register_business_logic.dart:22:27 • close_sinks
   info • Close instances of `dart.core.Sink` • lib/page_me/register_business_logic.dart:40:20 • close_sinks
   info • Name non-constant identifiers using lowerCamelCase • lib/page_me/register_business_logic.dart:56:8 • non_constant_identifier_names
   info • The declaration '_handleRegisterError' isn't referenced • lib/page_me/register_business_logic.dart:163:8 • unused_element
   info • This function has a return type of 'Future<dynamic>', but doesn't end with a return statement • lib/page_me/reigister_api.dart:130:19 • missing_return
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: CountryPicker._selected, CountryPicker.countries • lib/page_me/rename/country_picker.dart:8:7 • must_be_immutable
   info • The value of the field '_selected' isn't used • lib/page_me/rename/country_picker.dart:9:10 • unused_field
   info • Unused import: 'package:ulu_platform_demo/widgets/back_button_custom.dart' • lib/page_me/rename/rename_page.dart:5:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: RenamePage._text • lib/page_me/rename/rename_page.dart:8:7 • must_be_immutable
   info • Unused import: 'package:ulu_platform_demo/page_me/binding_bloc.dart' • lib/page_me/security_page.dart:10:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/email_register.dart' • lib/page_me/security_page.dart:11:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/user_controller.dart' • lib/page_me/security_page.dart:14:8 • unused_import
   info • The value of the local variable 'lc' isn't used • lib/page_me/security_page.dart:28:11 • unused_local_variable
   info • 'showSnackBar' is deprecated and shouldn't be used. Use ScaffoldMessenger.showSnackBar. This feature was deprecated after v1.23.0-14.0.pre. • lib/page_me/security_page.dart:96:46 • deprecated_member_use
   info • 'showSnackBar' is deprecated and shouldn't be used. Use ScaffoldMessenger.showSnackBar. This feature was deprecated after v1.23.0-14.0.pre. • lib/page_me/security_page.dart:105:46 • deprecated_member_use
   info • 'showSnackBar' is deprecated and shouldn't be used. Use ScaffoldMessenger.showSnackBar. This feature was deprecated after v1.23.0-14.0.pre. • lib/page_me/security_page.dart:118:42 • deprecated_member_use
   info • 'FlatButton' is deprecated and shouldn't be used. Use TextButton instead. See the migration guide in flutter.dev/go/material-button-migration-guide). This feature was deprecated after v1.25.0-8.1.pre. • lib/page_me/security_page.dart:134:17 •
          deprecated_member_use
   info • Unused import: 'package:ulu_platform_demo/widgets/snack_bar.dart' • lib/page_me/setting.dart:9:8 • unused_import
   info • Unused import: 'package:url_launcher/url_launcher.dart' • lib/page_me/setting.dart:21:8 • unused_import
   info • The value of the local variable 'lc' isn't used • lib/page_me/setting.dart:112:11 • unused_local_variable
   info • Unused import: 'package:country_code_picker/country_code_picker.dart' • lib/page_me/user_center.dart:4:8 • unused_import
   info • Unused import: 'package:flushbar/flushbar.dart' • lib/page_me/user_center.dart:5:8 • unused_import
   info • Unused import: 'package:sign_in_with_apple/sign_in_with_apple.dart' • lib/page_me/user_center.dart:8:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/email_login.dart' • lib/page_me/user_center.dart:10:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/register_business_logic.dart' • lib/page_me/user_center.dart:15:8 • unused_import
   info • 'FlatButton' is deprecated and shouldn't be used. Use TextButton instead. See the migration guide in flutter.dev/go/material-button-migration-guide). This feature was deprecated after v1.25.0-8.1.pre. • lib/page_me/user_center.dart:133:21 •
          deprecated_member_use
   info • Unused import: 'package:cached_network_image/cached_network_image.dart' • lib/page_me/user_info.dart:4:8 • unused_import
   info • Unused import: 'package:country_code_picker/selection_dialog.dart' • lib/page_me/user_info.dart:5:8 • unused_import
   info • Unused import: 'package:flutter/gestures.dart' • lib/page_me/user_info.dart:7:8 • unused_import
   info • Unused import: 'package:intl/intl.dart' • lib/page_me/user_info.dart:11:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_me/change_avatar.dart' • lib/page_me/user_info.dart:16:8 • unused_import
   info • The value of the field '_nickname' isn't used • lib/page_me/user_info.dart:41:10 • unused_field
   info • The value of the field '_name' isn't used • lib/page_me/user_info.dart:42:10 • unused_field
   info • The value of the field '_birthday' isn't used • lib/page_me/user_info.dart:43:10 • unused_field
   info • The value of the field '_gender' isn't used • lib/page_me/user_info.dart:44:7 • unused_field
   info • The value of the field '_country' isn't used • lib/page_me/user_info.dart:45:10 • unused_field
   info • The value of the local variable 'lc' isn't used • lib/page_me/user_info.dart:55:11 • unused_local_variable
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: InfoPageInner.currentInfo, InfoPageInner.editing • lib/page_me/user_info.dart:117:7 • must_be_immutable
   info • The value of the field '_selected' isn't used • lib/page_me/user_info.dart:144:11 • unused_field
   info • The value of the field '_dateTime' isn't used • lib/page_me/user_info.dart:146:12 • unused_field
warning • The parameter 'onPressed' is required • lib/page_me/user_info.dart:266:19 • missing_required_param
warning • The parameter 'onPressed' is required • lib/page_me/user_info.dart:321:21 • missing_required_param
warning • The parameter 'onPressed' is required • lib/page_me/user_info.dart:419:23 • missing_required_param
warning • The parameter 'onPressed' is required • lib/page_me/user_info.dart:521:23 • missing_required_param
warning • The parameter 'onPressed' is required • lib/page_me/user_info.dart:574:23 • missing_required_param
   info • Avoid using braces in interpolation when not needed • lib/page_me/user_info.dart:600:41 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/page_me/user_info.dart:617:41 • unnecessary_brace_in_string_interps
   info • The value of the local variable 'params' isn't used • lib/page_me/user_info.dart:661:11 • unused_local_variable
   info • The value of the local variable 'header' isn't used • lib/page_me/user_info.dart:663:11 • unused_local_variable
   info • This function has a return type of 'FutureOr<bool>', but doesn't end with a return statement • lib/page_me/user_info.dart:672:16 • missing_return
   info • 'await' applied to 'void', which is not a 'Future' • lib/page_me/user_info.dart:682:5 • await_only_futures
   info • Unused import: 'package:provider/provider.dart' • lib/user_controller.dart:6:8 • unused_import
   info • Unused import: 'package:path/path.dart' • lib/user_controller.dart:15:8 • unused_import
   info • Duplicate import • lib/user_controller.dart:17:8 • duplicate_import
   info • Avoid using braces in interpolation when not needed • lib/user_controller.dart:39:29 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/user_controller.dart:65:19 • unnecessary_brace_in_string_interps
   info • Avoid using braces in interpolation when not needed • lib/user_controller.dart:65:38 • unnecessary_brace_in_string_interps
   info • 'await' applied to 'void', which is not a 'Future' • lib/user_controller.dart:89:7 • await_only_futures
   info • This method overrides a method annotated as '@mustCallSuper' in 'ChangeNotifier', but doesn't invoke the overridden method • lib/user_controller.dart:126:3 • must_call_super
   info • 'await' applied to 'void', which is not a 'Future' • lib/user_controller.dart:133:5 • await_only_futures
   info • Unused import: 'package:flutter/scheduler.dart' • lib/widgets/list_content_widget.dart:4:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/miscellaneous/notification_provider.dart' • lib/widgets/list_content_widget.dart:9:8 • unused_import
   info • Unused import: 'package:ulu_platform_demo/page_infos/backend/story_list_provider.dart' • lib/widgets/list_content_widget.dart:10:8 • unused_import
   info • Unused import: '../user_controller.dart' • lib/widgets/list_content_widget.dart:11:8 • unused_import
   info • Avoid using braces in interpolation when not needed • lib/widgets/list_content_widget.dart:80:61 • unnecessary_brace_in_string_interps
   info • This method overrides a method annotated as '@mustCallSuper' in 'AutomaticKeepAliveClientMixin', but doesn't invoke the overridden method • lib/widgets/list_content_widget.dart:95:10 • must_call_super
   info • The value of the local variable 'lc' isn't used • lib/widgets/list_content_widget.dart:99:11 • unused_local_variable
   info • Avoid using braces in interpolation when not needed • lib/widgets/list_content_widget.dart:134:53 • unnecessary_brace_in_string_interps
   info • The receiver uses '?.', so its value can be null • lib/widgets/list_content_widget.dart:135:13 • can_be_null_after_null_aware
   info • Unused import: 'package:flutter_html/style.dart' • lib/widgets/mini_button.dart:5:8 • unused_import
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: ULUNavigationBar.title, ULUNavigationBar.onBackButtonPressed, ULUNavigationBar.showleading,
          ULUNavigationBar.leadingImage, ULUNavigationBar.trailingWidget • lib/widgets/navigation_bar.dart:6:7 • must_be_immutable
   info • This class (or a class that this class inherits from) is marked as '@immutable', but one or more of its instance fields aren't final: Flushbar.onStatusChanged, Flushbar._flushbarRoute • lib/widgets/snack_bar.dart:5:7 • must_be_immutable
   info • Unused import: 'package:ulu_platform_demo/model/model_class.dart' • lib/widgets/update_notice.dart:6:8 • unused_import
   info • Unused import: 'package:url_launcher/url_launcher.dart' • lib/widgets/update_notice.dart:11:8 • unused_import
   info • The value of the local variable 'args' isn't used • lib/widgets/update_notice.dart:29:11 • unused_local_variable
warning • Publishable packages can't have git dependencies • pubspec.yaml:55:5 • invalid_dependency

392 issues found. (ran in 9.3s)

```

<!-- Finally, paste the output of running `flutter doctor -v` here. -->
## flutter doctor -v 
```
[✓] Flutter (Channel stable, 2.0.2, on Mac OS X 10.15.7 19H524 darwin-x64, locale zh-Hans-CN)
    • Flutter version 2.0.2 at /Users/wangshuzhu/flutter
    • Framework revision 8962f6dc68 (8 days ago), 2021-03-11 13:22:20 -0800
    • Engine revision 5d8bf811b3
    • Dart version 2.12.1
    • Pub download mirror https://pub.flutter-io.cn
    • Flutter download mirror https://storage.flutter-io.cn

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at /Users/wangshuzhu/Library/Android/sdk
    • Platform android-30, build-tools 30.0.3
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.4, Build version 12D4e
    • CocoaPods version 1.10.0

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)

[✓] VS Code (version 1.53.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.19.0


```

</details>