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: "nanopub java a java library for nanopublications"
  Abstract: The concept of nanopublications was first proposed about six years ago, but it lacked openly available implementations. The library presented here is the first one that has become an official implementation of the nanopublication community. Its core features are stable, but it also contains unofficial and experimental extensions: for publishing to a decentralized server network, for defining sets of nanopublications with indexes, for informal assertions, and for digitally signing nanopublications. Most of the features of the library can also be accessed via an online validator interface.

Connected through hyperedge HE-1 (induced by source paper "nanopublications a growing resource of provenance centric scientific linked data"):
  with members:
    - "reliable granular references to changing linked data"
    - "making digital artifacts on the web verifiable and reliable"
    - "provenance centered dataset of drug drug interactions"
    - "trusty uris verifiable immutable and permanent digital artifacts for linked data"
    - "publishing without publishers a decentralized approach to dissemination retrieval and archiving of data"
    - "micropublications a semantic model for claims evidence arguments and annotations in biomedical communications"
    - "broadening the scope of nanopublications"

Connected through hyperedge HE-2 (induced by source paper "reliable granular references to changing linked data"):
  with members:
    - "making digital artifacts on the web verifiable and reliable"
    - "provenance centered dataset of drug drug interactions"
    - "trusty uris verifiable immutable and permanent digital artifacts for linked data"
    - "publishing without publishers a decentralized approach to dissemination retrieval and archiving of data"
    - "broadening the scope of nanopublications"
    - "an http based versioning mechanism for linked data"

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)