code: protected void populateIndexingRules( LinkedList<OptimizerRule> ruleStack,
                                            PlanHints hints ) {
          ruleStack.addLast(AddIndexes.implicitIndexes());
      }
docs: Method that is used to add the indexing rules to the rule stack. This method can be overridden by subclasses when custom
  indexing rules are to be used. By default, this method simply adds the {@link AddIndexes} rule.
  
  @param ruleStack the stack where the rules should be placed; never null
  @param hints the plan hints