def METHOD_NAME():
    n_images, n_rows, n_cols = 3, 2, 3
    arr_in = np.arange(n_images * n_rows * n_cols, dtype=float)
    arr_in = arr_in.reshape(n_images, n_rows, n_cols)
    arr_out = montage(arr_in, fill=0)
    arr_ref = np.array(
        [[  0. ,   1. ,   2. ,   6. ,   7. ,   8. ],
         [  3. ,   4. ,   5. ,   9. ,  10. ,  11. ],
         [ 12. ,  13. ,  14. ,   0. ,   0. ,   0. ],
         [ 15. ,  16. ,  17. ,   0. ,   0. ,   0. ]]
    )
    assert_array_equal(arr_out, arr_ref)