public function copyDropzone(Dropzone $dropzone, DropZone $newDropzone)
    {
        foreach ($dropzone->getCriteria() as $criterion) {
            $newCriterion = new Criterion();
            $newCriterion->setDropzone($newDropzone);
            $newCriterion->setInstruction($criterion->getInstruction());
            $this->om->persist($newCriterion);
        }

        return $newDropzone;
    }