def __create_action(self, main_root):
		action_dir = os.path.join(main_root, 'action')
		safe_mkdir(action_dir)

		actions = set()
		for unit, param in self.__task.data['workflow'].items():
			actions.add(param['type'])
		self.__action_mgr.create_actions(actions, action_dir)
def kth(root, k):
    if k < size(root.left):
        return kth(root.left, k)
    elif k > size(root.left):
        return kth(root.right, k - size(root.left) - 1)
    return root.key