code: function _hashQuads(id, bnodes, namer) {
    // return cached hash
    if('hash' in bnodes[id]) {
      return bnodes[id].hash;
    }
  
    // serialize all of bnode's quads
    var quads = bnodes[id].quads;
    var nquads = [];
    for(var i = 0; i < quads.length; ++i) {
      nquads.push(_toNQuad(
        quads[i], quads[i].name ? quads[i].name.value : null, id));
    }
    // sort serialized quads
    nquads.sort();
    // return hashed quads
    var hash = bnodes[id].hash = sha1.hash(nquads);
    return hash;
  }
docs: Hashes all of the quads about a blank node.
  
  @param id the ID of the bnode to hash quads for.
  @param bnodes the mapping of bnodes to quads.
  @param namer the canonical bnode namer.
  
  @return the new hash.