human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "the evolution of contracts"):
  Abstract: Contracts are a form of lightweight formal specification embedded in the program text. Being executable parts of the code, they encourage programmers to devote the proper attention to specifications and help maintain consistency between specification and implementation as the program evolves. For verification, contracts can be evaluated at run time, and hence support dynamic analysis. The present study investigates the connection between contracts and software evolution. Based on an extensive empirical analysis of 15 contract-equipped Eiffel and C# projects totaling 5900 revisions, it explores, among other questions: 1) how contracts change over time; 2) which kinds of contract element (preconditions, postconditions, class invariants) are used more often; 3) the relationship between code change and contract change frequencies; and 4) the role of inheritance in the process. It has found, among other results, that: the percentage of program elements that include contracts is above 33% for most projects and tends to be stable over time; there is no strong preference for a certain type of contract element; contracts are quite stable compared to implementations; and inheritance does not significantly affect qualitative trends of contract usage.

Includes members:
  Member "class schema evolution for persistent object oriented software model empirical study and automated support":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "contracts in practice")
  Member "stateful testing finding more errors in code and contracts":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "contracts in practice")

Question: Please tell me which class the source paper 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)