code: def validate_default_element(self, value):
          
          if isinstance(value, (six.string_types, six.integer_types)):
              # Validation of the value does not happen for delayed resolution
              # enumerated types.  Ignore if type is not yet resolved.
              if self.__type:
                  self.__type(value)
              return value
  
          return super(EnumField, self).validate_default_element(value)
docs: Validate default element of Enum field.
  
          Enum fields allow for delayed resolution of default values
          when the type of the field has not been resolved. The default
          value of a field may be a string or an integer. If the Enum
          type of the field has been resolved, the default value is
          validated against that type.
  
          Args:
            value: Value to validate.
  
          Raises:
            ValidationError if value is not expected message type.