/** * Implementation of custom clone method since * native php __clone raises error in Flow. * Override in exercises which have additional references to objects. */ public function postClone() { if (is_object($this->image)) { $this->image = $this->image->copy(); } if (is_object($this->pdfFile)) { $this->pdfFile = $this->pdfFile->copy(); } if (is_object($this->soundFile)) { $this->soundFile = $this->soundFile->copy(); } }