Olli Johnson

Proposed fix for #44 Adds a new severity symbol "O" (i.e. call-Overload). This new severity acts as "E" but activates suppression of note messages on the same line. Documentation and...

For a "[call-overload]" error mypy raises an `error` and multiple `note` messages. Since we can't test for multiple messages on the same line its currently not possible to successfully test...