original_string: private function createWorker()
      {
          $worker = $this->factory->create();
          $worker->start();
  
          $this->workers->attach($worker, 0);
          return $worker;
      }
code: private function createWorker()
      {
          $worker = $this->factory->create();
          $worker->start();
  
          $this->workers->attach($worker, 0);
          return $worker;
      }
code_tokens: private function createWorker ( ) { $ worker = $ this -> factory -> create ( ) ; $ worker -> start ( ) ; $ this -> workers -> attach ( $ worker , 0 ) ; return $ worker ; }
docstring: Creates a worker and adds them to the pool.
  
  @return Worker The worker created.
docstring_tokens: Creates a worker and adds them to the pool .