docs: def create_custom_field(self, field_name, data_type, options=[],
                              visible_in_preference_center=True):
          """Creates a new custom field for this list."""
          body = {
              "FieldName": field_name,
              "DataType": data_type,
              "Options": options,
              "VisibleInPreferenceCenter": visible_in_preference_center}
          response = self._post(self.uri_for("customfields"), json.dumps(body))
          return json_to_py(response)