code: def evaluate(self, x, y, flux, x_0, y_0):
          
  
          if self.xname is None:
              dx = x - x_0
          else:
              dx = x
              setattr(self.psfmodel, self.xname, x_0)
  
          if self.xname is None:
              dy = y - y_0
          else:
              dy = y
              setattr(self.psfmodel, self.yname, y_0)
  
          if self.fluxname is None:
              return (flux * self._psf_scale_factor *
                      self._integrated_psfmodel(dx, dy))
          else:
              setattr(self.psfmodel, self.yname, flux * self._psf_scale_factor)
              return self._integrated_psfmodel(dx, dy)
docs: The evaluation function for PRFAdapter.