code: def containment_angle(self, energies=None, fraction=0.68, scale_fn=None):
          
  
          if energies is None:
              energies = self.energies
  
          vals = self.interp(energies[np.newaxis, :], self.dtheta[:, np.newaxis],
                             scale_fn=scale_fn)
          dtheta = np.radians(self.dtheta[:, np.newaxis] * np.ones(vals.shape))
          return self._calc_containment(dtheta, vals, fraction)
docs: Evaluate the PSF containment angle at a sequence of energies.