public function getLastVersion($post_id)
	{
		$qb = $this->createQueryBuilder('p');
		
		$qb->where('p.original=:post_id')
			->orderBy('p.createdAt', 'DESC')
			->setParameter(':post_id', $post_id);
		
		$result = $qb->getQuery()->setMaxResults(1)->getResult(Query::HYDRATE_OBJECT);
		
		if ( is_null($result) ) {
			$qb2 = $this->createQueryBuilder('p');
			$qb2->where('p.id=:post_id')->setParameter(':post_id', $post_id);
			
			$result = $qb->getQuery()->getResult(Query::HYDRATE_OBJECT);
		}
		
		return $result;
	}