code: def add_to_dumper(dumper: Type, classes: List[Type]) -> None:
      
      if not isinstance(classes, list):
          classes = [classes]  # type: ignore
      for class_ in classes:
          if issubclass(class_, enum.Enum):
              dumper.add_representer(class_, EnumRepresenter(class_))
          elif issubclass(class_, str) or issubclass(class_, UserString):
              dumper.add_representer(class_, UserStringRepresenter(class_))
          else:
              dumper.add_representer(class_, Representer(class_))
docs: Register user-defined classes with the Dumper.
  
      This enables the Dumper to write objects of your classes to a \
      YAML file. Note that all the arguments are types, not instances!
  
      Args:
          dumper: Your dumper class(!), derived from yatiml.Dumper
          classes: One or more classes to add.