Wan, Yao, He, Yang, Yu, Philip S., Bi, Zhangqian, Zhang, Jianguo, Sui, Yulei, Zhang, Hongyu, Hashimoto, Kazuma, Jin, Hai, Xu, Guandong, Xiong, Caiming. Institute of Electrical and Electronics Engineers (IEEE); 2022. NaturalCC: An Open-Source Toolkit for Code Intelligence.