def nonisomorphic_trees(order, create="graph"):

    if order < 2:
        raise ValueError
    # start at the path graph rooted at its center
    layout = list(range(order // 2 + 1)) + list(range(1, (order + 1) // 2))

    while layout is not None:
        layout = _next_tree(layout)
        if layout is not None:
            if create == "graph":
                yield _layout_to_graph(layout)
            elif create == "matrix":
                yield _layout_to_matrix(layout)
            layout = _next_rooted_tree(layout)
Decorator raising SkipTest if the OS is `sysname` and the version is less
dataset/ETHPy150Open networkx/networkx/networkx/generators/nonisomorphic_trees.py/nonisomorphic_trees--crossover with--dataset/ETHPy150Open OpenCobolIDE/OpenCobolIDE/open_cobol_ide/extlibs/future/backports/test/support.py/_requires_unix_version