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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def evaluate(self, x, y, flux, x_0, y_0):
 """The evaluation function for PRFAdapter."""


        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)