code: public static PublishNotify createPublishNotify(Identifier i1, Identifier i2,
  			Document md) {
  
  		if (md == null) {
  			throw new NullPointerException("md is null");
  		}
  
  		List<Document> mdlist = new ArrayList<Document>(1);
  		mdlist.add(md);
  
  		return createPublishNotify(i1, i2, mdlist);
  	}
docs: Create a new {@link PublishNotify} instance that is used to publish
  metadata on a link between two {@link Identifier} instances.
  
  @param i1 the first {@link Identifier} of the link
  @param i2 the second {@link Identifier} of the link
  @param md the metadata that shall be published
  @return the new {@link PublishNotify} instance