code: def make_choices_tuple(choices, get_display_name):
      
      assert callable(get_display_name)
      return tuple((x, get_display_name(x)) for x in choices)
docs: Make a tuple for the choices parameter for a data model field.
  
      :param choices: sequence of valid values for the model field
      :param get_display_name: callable that returns the human-readable name for a choice
  
      :return: A tuple of 2-tuples (choice, display_name) suitable for the choices parameter