code: def _method_complete(self, result):
      
      if isinstance(result, PrettyTensor):
        self._head = result
        return self
      elif isinstance(result, Loss):
        return result
      elif isinstance(result, PrettyTensorTupleMixin):
        self._head = result[0]
        return result
      else:
        self._head = self._head.with_tensor(result)
        return self
docs: Called after an extention method with the result.