src/Zf2Forum/Model/Topic/TopicMapper.php
protected function insert($entity, $tableName = null, HydratorInterface $hydrator = null)
    {
        $result = parent::insert($entity, $tableName, $hydrator);
        $entity->setId($result->getGeneratedValue());
        return $result;
    }
protected function insert($entity, $tableName = null, HydratorInterface $hydrator = null)
    {
        $result = parent::insert($entity, $tableName, $hydrator);
        $entity->setId($result->getGeneratedValue());
        return $result;
    }
insert - Inserts a new thread into the database, using the specified hydrator.

@param ThreadInterface $entity
@param String $tableName
@param HydratorInterface $hydrator
@return unknown