public Iterator candidateKeyMethods(Filter keyMethodFilter) {
   return (this.getReferenceDescriptor() == null)
       ? NullIterator.instance()
       : new FilteringIterator(
           this.getReferenceDescriptor().getMWClass().allInstanceMethods(), keyMethodFilter);
 }
 public Iterator baseBuiltInTypes() {
   return NullIterator.instance();
 }
 public Iterator candidateKeyMethods() {
   MWDescriptor refDescriptor = this.getMapContainerMapping().getReferenceDescriptor();
   return (refDescriptor != null)
       ? refDescriptor.getMWClass().candidateMapContainerPolicyKeyMethods()
       : NullIterator.instance();
 }
 /**
  * Return an iterator on the items that were added to or removed from the collection. May be empty
  * if inappropriate or unknown.
  */
 public Iterator items() {
   if (this.items == null) {
     return NullIterator.instance();
   }
   return new ReadOnlyIterator(this.items);
 }