'Tests appending a Simple GroupsHDU to an empty HDUList.'

@raises(ValueError)
def test_append_groupshdu_to_non_empty_list(self):

    hdul = fits.HDUList()
    hdu = fits.PrimaryHDU(np.arange(100, dtype=np.int32))
    hdul.append(hdu)
    hdu = fits.GroupsHDU()
    hdul.append(hdu)
