def METHOD_NAME(self):
    #- Setup data for a Resolution matrix
    spectra = self._get_spectra()
    sky = compute_sky(spectra,add_variance=self.add_variance)
    self.assertEqual(sky.flux.shape, spectra.flux.shape)
    self.assertEqual(sky.ivar.shape, spectra.ivar.shape)
    self.assertEqual(sky.mask.shape, spectra.mask.shape)
    delta=spectra.flux[0]-sky.flux[0]
    d=np.inner(delta,delta)
    self.assertAlmostEqual(d,0.)
    delta=spectra.flux[-1]-sky.flux[-1]
    d=np.inner(delta,delta)
    self.assertAlmostEqual(d,0.)