Method _unlock

/**
 * Method to unlock the database table for writing.
 *
 * @return  boolean  True on success.
 *
 * @since   1.7.0
 */
protected function _unlock()
{
    if ($this->_locked) {
        $this->_db->unlockTables();
        $this->_locked = false;
    }
    return true;
}