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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def walk(zk, path='/'):
 """Yields all paths under `path`."""

    children = zk.get_children(path)
    yield path
    for child in children:
        if path == '/':
            subpath = "/%s" % child
        else:
            subpath = "%s/%s" % (path, child)

        for child in walk(zk, subpath):
            yield child