code: public function present()
      {
          $presenterClass = $this->getPresenterClass();
  
          if (!class_exists($presenterClass)) {
              throw new Exceptions\PresenterException('The specified presenter does not exist.');
          }
  
          if (!$this->presenterInstance) {
              $this->presenterInstance = new $presenterClass($this);
          }
  
          return $this->presenterInstance;
      }
docs: Prepare a new or cached presenter instance.
  
  @throws PresenterException
  
  @return mixed