Fixes that mypy plugin was failing on calling a typeclass without arguments

[sobolevn]

Closes #270

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (779b040) to head (ec2cbae).
⚠️ Report is 160 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##            master      #273   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            3         3           
  Lines           99        99           
  Branches        16        16           
=========================================
  Hits            99        99           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.