Doctrine\ODM\MongoDB\DocumentManager::remove PHP Method

    public function remove($document)
    {
        if (!is_object($document)) {
            throw new \InvalidArgumentException(gettype($document));
        }
        $this->errorIfClosed();
        $this->unitOfWork->remove($document);
    }

 /**
  * @param Item        $item
  * @param string|null $collection
  * @return Item
  */
 public function delete($item, $collection = null)
 {
     $this->setCollection($collection);
     $this->dm->remove($item);
     $this->dm->flush();
     return $item;
 }