fix type hint.
Merge pull request #5579 in master
Merge pull request #5532
Merge pull request #5532 from zhanxu/patch-1

fix type hint.
Merge pull request #5532 into master
Back-port of copyright changes to master

Diff based on PR #5654 (git diff a961e19..fd935cf), applied skipping unmatched files
Merge branch 'hotfix/ViewHelperCleanup'