docs: def update_pixel_location(self, new_pixel_location, hdu_index):
          """
          Update the x/y location of the associated reading by using new_pixel_location and transforming from cutout
          reference frame to observation refrence frame.
          @param new_pixel_location: (x, y) location of the source in cutout pixel reference frame
          @param hdu_index: index of the associate hdu in the hdulist for this cutout
          """
          self.reading.pix_coord = self.get_observation_coordinates(new_pixel_location[0],
                                                                    new_pixel_location[1],
                                                                    hdu_index)
          new_ccd = self.get_ccdnum(hdu_index)
          if new_ccd != self.reading.get_ccd_num():
              self._apcor = None
              self._zmag = None
              self.reading.obs.ccdnum = self.get_ccdnum(hdu_index)
          self.reading.sky_coord = self.pix2world(new_pixel_location[0],
                                                  new_pixel_location[1],
                                                  hdu_index)