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: "flexible and extensible digital object and repository architecture fedora"
  Abstract: We describe a digital object and respository architecture for storing and disseminating digital library content. The key features of the architecture are: (1) support for heterogeneous data types; (2) accommodation of new types as they emerge; (3) aggregation of mixed, possibly distributed, data into complex objects; (4) the ability to specify multiple content disseminations of these objects; and (5) the ability to associate rights management schemes with these disseminations. This architecture is being implemented in the context of a broader research project to develop next-generation service modules for a layered digital library architecture.

Connected through hyperedge HE-1 (induced by source paper "the mellon fedora project digital library architecture meets xml and web services"):
  with members:
    - "policy carrying policy enforcing digital objects"

Connected through hyperedge HE-2 (induced by source paper "fedora an architecture for complex objects and their relationships"):
  with members:
    - "policy carrying policy enforcing digital objects"
    - "the mellon fedora project digital library architecture meets xml and web services"
    - "adore a modular standards based digital object repository"
    - "an information network overlay architecture for the nsdl"

Connected through hyperedge HE-3 (induced by source paper "an information network overlay architecture for the nsdl"):
  with members:
    - "the mellon fedora project digital library architecture meets xml and web services"
    - "fedora an architecture for complex objects and their relationships"
    - "core services in the architecture of the national digital library for science education nsdl"

Connected through hyperedge HE-4 (induced by source paper "access interfaces for open archival information systems based on the oai pmh and the openurl framework for context sensitive services"):
  with members:
    - "adore a modular standards based digital object repository"

Connected through hyperedge HE-5 (induced by source paper "using structural metadata to localize experience of digital content"):
  with members:
    - "policy carrying policy enforcing digital objects"

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.DL(Digital Libraries)