human
I wrote the below code

    def dfs(elem):
        for v in get_children(elem):
            for u in dfs(v):
                (yield u)
        (yield elem)
    for elem in dfs(root):
        (yield elem)

What's a good function header?

Here's a good function header?
assistant
#Here's a good function header.

def _postorder_traverse(root, get_children):