code: def check(self, feature):
          
          mapper = feature.as_dataframe_mapper()
          X = mapper.fit_transform(self.X, y=self.y)
          assert self.X.shape[0] == X.shape[0]
docs: Check that the dimensions of the transformed data are correct
  
          For input X, an n x p array, a n x q array should be produced,
          where q is the number of features produced by the logical feature.