public function findByRoleId($roleId)
    {
        $select = $this->getSelect($this->getUserTableName());
        $select->where(array($this->getTableName() . '.role_id' => $roleId));
        $select->join(
            $this->getTableName(),
            $this->getTableName(). '.user_id = ' . $this->getUserTableName(). '.user_id',
            array(),
            Select::JOIN_INNER
        );
        $select->group($this->getUserTableName(). '.user_id');

        $entityPrototype = $this->getZfcUserOptions()->getUserEntityClass();

        return $this->select($select, new $entityPrototype, $this->getZfcUserHydrator());
    }