gistfile1.php

<?php

abstract class DoctrineRepository extends \Doctrine\ORM\EntityRepository
{
    public function add($entity)
    {
        $this->checkEntity($entity);

        $this->_em->persist($entity);
    }

    public function remove($entity)
    {
        $this->checkEntity($entity);

        $this->_em->remove($entity);
    }


    private function checkEntity($entity)
    {
        if (!is_object($entity)) {
            throw new \UnexpectedValueException(sprintf(
                'An object was expected, given %s.', gettype($entity)));
        }

        if (!$entity instanceOf $this->_class->name) {
            throw new \UnexpectedValueException(sprintf(
                '%s is not an instance of %s.', get_class($entity), $this->getEntityName()));
        }
    }
}