Repository: huggingface/transformers
Pull request: Export base streamer.

Previously, the base streamer class was not exported so the set of available streamers was fixed to 3 streamer classes. 

This change makes it so that customers may extend the default base streamer class.

# What does this PR do?
Previously, the base streamer class was not exported so the set of available streamers was fixed to 3 streamer classes. 

This change makes it so that customers may extend the default base streamer class.


Fixes # (issue)

None
## Before submitting
- [X-no ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [ ] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#create-a-pull-request),
      Pull Request section?
- [X-no ] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link
      to it if that's the case.
- [X-no ] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [X ] Did you write any new necessary tests?


## Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.

<!-- Your PR will be replied to more quickly if you can figure out the right person to tag with @

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 Please tag fewer than 3 people.

Models:

- text models: @ArthurZucker
- vision models: @amyeroberts, @qubvel
- speech models: @ylacombe, @eustlb
- graph models: @clefourrier

Library:

- flax: @sanchit-gandhi
- generate: @zucchini-nlp (visual-language models) or @gante (all others)
- pipelines: @Rocketknight1
- tensorflow: @gante and @Rocketknight1
- tokenizers: @ArthurZucker
- trainer: @muellerzr and @SunMarc
- chat templates: @Rocketknight1

Integrations:

- deepspeed: HF Trainer/Accelerate: @muellerzr
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Changed files:
filename: src/transformers/generation/__init__.py
patch: @@ -26,7 +26,7 @@
         "SynthIDTextWatermarkingConfig",
         "WatermarkingConfig",
     ],
-    "streamers": ["AsyncTextIteratorStreamer", "TextIteratorStreamer", "TextStreamer"],
+    "streamers": ["AsyncTextIteratorStreamer", "BaseStreamer", "TextIteratorStreamer", "TextStreamer"],
 }
 
 try:
@@ -197,7 +197,7 @@
         SynthIDTextWatermarkingConfig,
         WatermarkingConfig,
     )
-    from .streamers import AsyncTextIteratorStreamer, TextIteratorStreamer, TextStreamer
+    from .streamers import AsyncTextIteratorStreamer, BaseStreamer, TextIteratorStreamer, TextStreamer
 
     try:
         if not is_torch_available():