code: def get_results(self, **kwargs):
          
          # Check whether the process completed.
          if self.returncode is None:
              raise self.Error("return code is None, you should call wait, communicate or poll")
  
          if self.status is None or self.status < self.S_DONE:
              raise self.Error("Task is not completed")
  
          return self.Results.from_node(self)
docs: Returns :class:`NodeResults` instance.
          Subclasses should extend this method (if needed) by adding
          specialized code that performs some kind of post-processing.