human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "collaborative software development on the web"
  Abstract: Software development environments (IDEs) have not followed the IT industry's inexorable trend towards distribution. They do too little to address the problems raised by today's increasingly distributed projects; neither do they facilitate collaborative and interactive development practices. A consequence is the continued reliance of today's IDEs on paradigms such as traditional configuration management, which were developed for earlier modes of operation and hamper collaborative projects. This contribution describes a new paradigm: cloud-based development, which caters to the specific needs of distributed and collaborative projects. The CloudStudio IDE embodies this paradigm by enabling developers to work on a shared project repository. Configuration management becomes unobtrusive; it replaces the explicit update-modify-commit cycle by interactive editing and real-time conflict tracking and management. A case study involving three teams of pairs demonstrates the usability of CloudStudio and its advantages for collaborative software development over traditional configuration management practices.

Connected through hyperedge HE-1 (induced by source paper "contracts in practice"):
  with members:
    - "flexible invariants through semantic collaboration"
    - "class schema evolution for persistent object oriented software model empirical study and automated support"
    - "what good are strong specifications"
    - "stateful testing finding more errors in code and contracts"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.SE(Software Engineering)