def METHOD_NAME():
    n_images, n_rows, n_cols = 6, 2, 2
    arr_in = np.arange(n_images * n_rows * n_cols, dtype=np.float32)
    arr_in = arr_in.reshape(n_images, n_rows, n_cols)
    arr_out = montage(arr_in, grid_shape=(3, 2))
    arr_ref = np.array(
        [[  0.,   1.,   4.,   5.],
         [  2.,   3.,   6.,   7.],
         [  8.,   9.,  12.,  13.],
         [ 10.,  11.,  14.,  15.],
         [ 16.,  17.,  20.,  21.],
         [ 18.,  19.,  22.,  23.]]
    )
    assert_array_equal(arr_out, arr_ref)