Zend_Service_Twitter でプロキシサーバを経由する方法

$client = new Zend_Http_Client(null, array(
    'adapter'    => 'Zend_Http_Client_Adapter_Proxy',
    'proxy_host' => 'proxyサーバのホスト名',
    'proxy_port' => proxyサーバのポート番号,
));

$twitter = new Zend_Service_Twitter(array(
    'accessToken' => $access_token, // Zend_Oauth_Token_Access
));
$twitter->setLocalHttpClient($client);