new_contents: from sqlalchemy import Column, ForeignKey, Integer, String
  from models import DecBase
  
  
  class Hash(DecBase):
      """ A document represents a single document shared to the network.
          Documents are indexed by tuples contained in their respective collections.
          Documents are stored and retreived from the Freenet network using the hashes
          in the index, and if full caching is enables, are cached on disk according
          to their age and the number of accesses tracked on this node.
  
          Attributes:
              collection_address: The address of the Collection the document is contained in. @todo investigate multiple collections
              description: The description of the document as stored in the latest known DocIndex
              hash: The SHA-256 hash of this document
              title: The title of the document as stored in the latest known DocIndex
              filename: The document filename on disk, or None if not stored
              accesses: The number of accesses the document has received on the FreeJournal network
      """
      __tablename__ = 'hash'
      id = Column(Integer, primary_key=True)
      hash = Column(String)
      document_ids = Column (String)
      collection_ver = Column(Integer)
  
subject: add hash.py