code: @Override
      public Document newDocument(Namespace namespace,
                                  Collection<Statement> statements,
                                  Collection<Bundle> bundles) {
  	Document res = of.createDocument();
  	res.setNamespace(namespace);
  	res.getStatementOrBundle()
  	   .addAll(statements);
  	res.getStatementOrBundle()
  	   .addAll(bundles);
  	return res;
      }
docs: /*
  (non-Javadoc)
  @see org.openprovenance.prov.model.ModelConstructor#newDocument(org.openprovenance.prov.model.Namespace, java.util.Collection, java.util.Collection)