/** @inheridDoc */
 public Evaluator getEvaluator(ValueType type, Operator operator, String parameterText) {
   return this.getEvaluator(
       type, operator.getOperatorString(), operator.isNegated(), parameterText);
 }
 /** @inheridDoc */
 public Evaluator getEvaluator(ValueType type, Operator operator) {
   return this.getEvaluator(type, operator.getOperatorString(), operator.isNegated(), null);
 }