How to use the meshzoo.refine function in meshzoo

np.array([0.0, 1.0, 0.0]),
        np.array([-0.5*np.sqrt(3.0), -0.5, 0.0]),
        np.array([0.5*np.sqrt(3.0), -0.5, 0.0])
        ])
    edges = np.array([
        np.array([0, 1]),
        np.array([0, 2]),
        np.array([1, 2])
        ])
    cells_nodes = np.array([[0, 1, 2]], dtype=int)
    cells_edges = np.array([[0, 1, 2]], dtype=int)

    # Refine.
    for _ in range(ref_steps):
        nodes, edges, cells_nodes, cells_edges = \
            refine.refine(nodes, edges, cells_nodes, cells_edges)

    return nodes, cells_nodes

np.array([0, 5, 6]),
        np.array([0, 6, 1])
        ])
    cells_edges = np.array([
        np.array([0, 6, 1]),
        np.array([1, 7, 2]),
        np.array([2, 8, 3]),
        np.array([3, 9, 4]),
        np.array([4, 10, 5]),
        np.array([5, 11, 0])
        ])

    # Refine.
    for k in range(ref_steps):
        nodes, edges, cells_nodes, cells_edges = \
            refine.refine(nodes, edges, cells_nodes, cells_edges)

    return nodes, cells_nodes