* Checks whether <code>att</code> has to be ignored with respect to
* the attribute filter in use. Otherwise <code>att</code> is added to
* the internal hash tables and the interned version of it is returned.
*/
public EntityAttribute intern(EntityAttribute att) {
EntityAttribute result = null;
// this version seems to have no measurable advantage:
// result = internedAttributes.get(att);
// if (result == null && !ignoredAttNames.contains(att.getName())
// && (!ignorePathNames || !att.getName().contains(":"))) {
// result = new EntityAttribute