protected function _addBranch(Zend_Config $config, $parents = array())
    {
        $iniString = '';

        foreach ($config as $key => $value) {
            $group = array_merge($parents, array($key));

            if ($value instanceof Zend_Config) {
                $iniString .= $this->_addBranch($value, $group);
            } else {
                $iniString .= implode($this->_nestSeparator, $group)
                           .  ' = '
                           .  $this->_prepareValue($value)
                           .  "\n";
            }
        }

        return $iniString;
    }