code: public function createInvoker($invoker)
      {
          $numberOfReporters = count($this->reporters);
          for ($i = 0; $i < $numberOfReporters; $i++) {
              $invoker = $this->reporters[$i]->createInvoker($invoker);
          }
  
          return $invoker;
      }
docs: Every reporter gets a chance to wrap the invoker.
  
  @param SimpleInvoker $invoker   Individual test runner.
  
  @return SimpleInvoker           Wrapped test runner.