def METHOD_NAME(mock_super_cal_name, mock_super_frame):
    mock_super_cal_name.return_value = {'filename': 'test.fits'}
    mock_super_frame.return_value = LCOCalibrationFrame(hdu_list=[CCDData(data=0.5*np.ones((100,100)),
                                                                          meta={'EXPTIME': 1.0,
                                                                                'SATURATE': 35000,
                                                                                'GAIN': 1.0,
                                                                                'MAXLIN': 35000,
                                                                                'ISMASTER': True,
                                                                                'CCDATEMP': -100})], file_path='/tmp')
    image = FakeLCOObservationFrame(hdu_list=[CCDData(data=4*np.ones((100,100)), meta={'EXPTIME': 2.0,
                                                                                        'SATURATE': 35000,
                                                                                        'GAIN': 1.0,
                                                                                        'MAXLIN': 35000,
                                                                                        'CCDATEMP': -100})])
    subtractor = DarkSubtractor(FakeContext())
    image = subtractor.do_stage(image)
    np.testing.assert_allclose(image.data, 3*np.ones((100,100)))