code: public static PublishDelete createPublishDelete(Identifier i1, Identifier i2,
  			String filter) {
  		PublishDelete pd = createPublishDelete();
  		fillIdentifierHolder(pd, i1, i2);
  		pd.setFilter(filter);
  		return pd;
  	}
docs: Create a new {@link PublishDelete} instance for a link between two
  {@link Identifier} instances in order to delete its metadata that matches
  the given filter.
  
  @param i1 the first {@link Identifier} of the link
  @param i2 the second {@link Identifier} of the link
  @param filter a filter that expresses the metadata that shall be deleted
  @return the new {@link PublishDelete} instance