issue-937 fix

[martins0n]

Before submitting (must do checklist)

• Did you read the contribution guide?
• Did you update the docs? We use Numpy format for all the methods and classes.
• Did you write any new necessary tests?
• Did you update the CHANGELOG?

Proposed Changes

Closing issues

closes #937

[github-actions]

🚀 Deployed on https://deploy-preview-941--etna-docs.netlify.app

[codecov-commenter]

Codecov Report

Merging #941 (51b14ca) into master (a02d2d6) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #941      +/-   ##
==========================================
+ Coverage   85.00%   85.01%   +0.01%     
==========================================
  Files         133      133              
  Lines        7614     7620       +6     
==========================================
+ Hits         6472     6478       +6     
  Misses       1142     1142              

Impacted Files	Coverage Δ
etna/core/mixins.py	95.71% <100.00%> (+0.40%)	⬆️

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[Mr-Geekman]

Answer questions above.

[Mr-Geekman]

Fix to pass lint stage and everything else is fine.