code: def shift(self, x=0, y=0):
          
          return self.deepcopy(self.x + x, self.y + y)
docs: Move the keypoint around on an image.
  
          Parameters
          ----------
          x : number, optional
              Move by this value on the x axis.
  
          y : number, optional
              Move by this value on the y axis.
  
          Returns
          -------
          imgaug.Keypoint
              Keypoint object with new coordinates.