code: def max_value_length(cls):
          
          if not hasattr(cls, '__max_value_length_'):
              cls.__max_value_length_ = max([len(c.value) for c in list(cls)])
          return cls.__max_value_length_
docs: Not to be used when using numeric values.
          
          Returns
          -------
          int
              the maximal length required by this Enum to be stored in the database