/**
  * Creates a new FarragoReduceExpressionsRule object.
  *
  * @param relClass class of rels to which this rule should apply
  */
 private FarragoReduceExpressionsRule(Class<? extends RelNode> relClass) {
   super(
       new RelOptRuleOperand(relClass, ANY),
       "FarragoReduceExpressionsRule:" + ReflectUtil.getUnqualifiedClassName(relClass));
 }