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

    public function remove($key)
    {
        $this->initialize();
        $removed = $this->coll->remove($key);
        if ($removed) {
            $this->changed();
            if ($this->mapping !== null && isset($this->mapping['embedded'])) {
                $this->dm->getUnitOfWork()->scheduleOrphanRemoval($removed);
            }
        }

        return $removed;
    }

 /**
  * {@inheritdoc}
  */
 public function remove($key)
 {
     return $this->collection->remove($key);
 }