def serialized(self):
        to_ret = {}
        for group, requirements in self.items():
            to_ret[group] = [str(requirement) for requirement in requirements]
        return to_ret
def json_usage(root):
    root = os.path.abspath(root)
    result = [['Path', 'Parent', 'Usage']]
    result.extend(entry for entry in usage_iter(root))
    return json.dumps(result)