def METHOD_NAME(Source):
    source = Source()
    e_img, e_crs, e_extent = source.combined(-1, 50, 2, 1)
    imgs = source.fetch_raster(ccrs.PlateCarree(),
                               (-0.9, 0.1, 50.1, 50.999),
                               None)
    assert len(imgs) == 1
    r_img, r_extent = imgs[0]
    assert e_extent == r_extent
    assert_array_equal(e_img[::-1, :], r_img)