code: def remove_optional(annotation: type):
      
      origin = getattr(annotation, '__origin__', None)
      args = getattr(annotation, '__args__', ())
      if origin == Union and len(args) == 2 and args[1] == type(None):
          return args[0]
      else:
          return annotation
docs: Optional[X] annotations are actually represented as Union[X, NoneType].
      For our purposes, the "Optional" part is not interesting, so here we
      throw it away.