docs: def to_primitive(self, context=None):
          """
          .. versionadded:: 1.3.0
          """
          primitive = super(VerboseMixin, self).to_primitive(context)
          to_text = lambda x: six.text_type(x) if x is not None else x
          primitive.update({
              'verbose_name': to_text(self.verbose_name),
              'help_text': to_text(self.help_text),
          })
          return primitive