public QueryBuilder<C,F> returnTheseAttributes(Collection<CoreTokenField> returnFields){
  Reject.ifTrue(returnFields == null || returnFields.isEmpty());
  Set<String> fields=new HashSet<String>();
  for (  CoreTokenField field : returnFields) {
    fields.add(field.toString());
  }
  return setReturnAttributes(fields);
}

public QueryBuilder < C , F > returnTheseAttributes ( Collection < CoreTokenField > returnFields ) { Reject . ifTrue ( returnFields == null || returnFields . isEmpty ( ) ) ; Set < String > fields = new HashSet < String > ( ) ; for ( CoreTokenField field : returnFields ) { fields . add ( field . toString ( ) ) ; } return setReturnAttributes ( fields ) ; }
limit the search to return only the named attributes .
