def METHOD_NAME():
    root = SIMPLE2.neurites[0].root_node
    assert bf.sibling_ratio(root) == 1.0
    assert bf.sibling_ratio(root.children[0]) == 1.0
    assert bf.sibling_ratio(root, method='mean') == 1.0
    assert bf.sibling_ratio(root.children[0], method='mean') == 1.0
    leaf = root.children[0].children[0]
    assert_raises(NeuroMError, bf.sibling_ratio, leaf)
    assert_raises(NeuroMError, bf.sibling_ratio, leaf, method='mean')
    multifurcation_section = MULTIFURCATION.neurites[0].root_node.children[0]
    assert_raises(NeuroMError, bf.sibling_ratio, multifurcation_section)
    assert_raises(ValueError, bf.sibling_ratio, root, method='unvalid-method')