code: def _format_type_in_doc(self, namespace, data_type):
          
          if is_void_type(data_type):
              return 'None'
          elif is_user_defined_type(data_type):
              return ':class:`{}.{}.{}`'.format(
                  self.args.types_package, namespace.name, fmt_type(data_type))
          else:
              return fmt_type(data_type)
docs: Returns a string that can be recognized by Sphinx as a type reference
          in a docstring.