code: public void unlink(ParaObject obj, String type2, String id2) {
  		if (obj == null || obj.getId() == null || type2 == null || id2 == null) {
  			return;
  		}
  		String url = Utils.formatMessage("{0}/links/{1}/{2}", obj.getObjectURI(), type2, id2);
  		invokeDelete(url, null);
  	}
docs: Unlinks an object from this one.
  Only a link is deleted. Objects are left untouched.
  @param type2 the other type
  @param obj the object to execute this method on
  @param id2 the other id