code: def detail(self, detail=None, ret_r=False):
          '''code's detail'''
          if detail or ret_r:
              self._detail = detail
              return self
          return self._detaif detail(self, detail=None, ret_r=False):
          '''code's detail'''
          if detail or ret_r:
              self._detail = detail
              return self
          return self._detail
docs: code's detail