code: def check(self, feature):
          
          try:
              buf = io.BytesIO()
              pickle.dump(feature, buf, protocol=pickle.HIGHEST_PROTOCOL)
              buf.seek(0)
              new_feature = pickle.load(buf)
              assert new_feature is not None
              assert isinstance(new_feature, Feature)
          finally:
              buf.close()
docs: Check that the feature can be pickled
  
          This is needed for saving the pipeline to disk