def is_positional_only_related(self) -> bool:
    'Whether or not the error is for something being (or not being) positional-only.'
    return ('leading double underscore' in self.message)
Whether or not the error is for something being (or not being) positional-only.
def is_positional_only_related(self) -> bool:
    
    return ('leading double underscore' in self.message)