code: def transform(self, X=None, y=None):
          
          # unpack zoom range
          zoom_x, zoom_y= self.zoom
  
          self.params = (zoom_x, zoom_y)
          zoom_matrix = np.array([[zoom_x, 0, 0],
                                  [0, zoom_y, 0]])
          self.tx.set_parameters(zoom_matrix)
          if self.lazy or X is None:
              return self.tx
          else:
              return self.tx.apply_to_image(X, reference=self.reference)
docs: Transform an image using an Affine transform with the given
          zoom parameters.   Return the transform if X=None.
  
          Arguments
          ---------
          X : ANTsImage
              Image to transform
  
          y : ANTsImage (optional)
              Another image to transform
  
          Returns
          -------
          ANTsImage if y is None, else a tuple of ANTsImage types
  
          Examples
          --------
          >>> import ants
          >>> img = ants.image_read(ants.get_data('r16'))
          >>> tx = ants.contrib.Zoom2D(zoom=(0.8,0.8,0.8))
          >>> img2 = tx.transform(img)