public function getStreamWrapperClassname($namespace, $protocol)
    {
        $namespace = (array) $namespace;
        $protocol = (array) $protocol;

        $result = array();
        foreach ($this->_streamWrappers as $ns => $wrappers) {
            if (true === in_array($ns, $namespace)) {
                foreach ($wrappers as $wrapper) {
                    if (true === in_array($wrapper['protocol'], $protocol)) {
                        $result[] = $wrapper['classname'];
                    }
                }
            }
        }

        return $result;
    }