def groups_option(f):
    new_func = click.option("-g", "--groups",
                            help="Comma-separated list of requirement groups "
                            "to include.")(f)
    return update_wrapper(new_func, f)
def __init__(self, key):
        self.key = key
        self.prio = random.randint(0, 1000000000)
        self.size = 1
        self.left = None
        self.right = None