'*' appears as a type hint bug in PyCharm when used as a converter key

[smarie]

from pyfields import field

class Foo(object):
    bar = field(type_hint=str, converters={'*': str}, check_type=True)

{'*': str} appears as a type error in PyCharm. We should use Literal['*'] and actually also str in the type hint since pycharm type checker does not seem to understand Literal yet.