Check that cast is not redundant [redundant-cast]

If you use —warn-redundant-casts, mypy will generate an error if the sourcetype of a cast is the same as the target type.

Example:

# mypy: warn-redundant-casts
 
from typing import cast
 
Count = int
 
def example(x: Count) -> int:
    # Error: Redundant cast to "int"  [redundant-cast]
    return cast(int, x)