def METHOD_NAME():
    rmg = RasterModelGrid((5, 4))
    expected = np.array(
        [
            [5, X, X, X],
            [6, 4, X, X],
            [7, 5, X, X],
            [X, 6, X, X],
            [9, X, X, 1],
            [10, 8, 0, 2],
            [11, 9, 1, 3],
            [X, 10, 2, X],
            [13, X, X, 5],
            [14, 12, 4, 6],
            [15, 13, 5, 7],
            [X, 14, 6, X],
            [17, X, X, 9],
            [18, 16, 8, 10],
            [19, 17, 9, 11],
            [X, 18, 10, X],
            [X, X, X, 13],
            [X, X, 12, 14],
            [X, X, 13, 15],
            [X, X, 14, X],
        ]
    )
    assert_array_equal(rmg.diagonal_adjacent_nodes_at_node, expected)