docs: public static IndexPlanner both( final IndexPlanner planner1,
                                       final IndexPlanner planner2 ) {
          if (planner1 == null) return planner2;
          if (planner2 == null) return planner1;
          return new IndexPlanner() {
  
              @Override
              public void applyIndexes( QueryContext context,
                                        IndexCostCalculator calculator ) {
                  RuntimeException error = null;
                  try {
                      planner1.applyIndexes(context, calculator);
                  } catch (RuntimeException e) {
                      error = e;
                  } finally {
                      try {
                          planner2.applyIndexes(context, calculator);
                      } catch (RuntimeException e) {
                          if (error == null) error = e;
                      } finally {
                          if (error != null) throw error;
                      }
                  }
              }
          };
      }