add type annotations to comm.py

[guilhermeleobas]

Fixes #46735

[dr-ci]

💊 CI failures summary and remediations

As of commit 6a95d25 (more details on the Dr. CI page):

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• 1/1 failures possibly* introduced in this PR
  • 1/1 non-CircleCI failure(s)

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codecov.io: 1 failed

• Failed: codecov/patch

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This comment has been revised 15 times.

[codecov]

Codecov Report

Merging #46736 into master will increase coverage by 0.00%.
The diff coverage is 50.00%.

@@           Coverage Diff           @@
##           master   #46736   +/-   ##
=======================================
  Coverage   68.96%   68.96%           
=======================================
  Files         434      434           
  Lines       55986    55987    +1     
=======================================
+ Hits        38612    38613    +1     
  Misses      17374    17374           

[facebook-github-bot]

@mrshenli has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[facebook-github-bot]

@mrshenli merged this pull request in 717e6d8.