PHP stream_context_create with proxy
===

I'm currently developing an web application which uses an XML Interface located on a different server, that I have to access via a proxy.

So I tried to set the proxy in a `stream_context_create` array, but it doesn't seem to work.

    $set = array(
        'http' => array(
            'method' => 'GET',
            'header' => sprintf(
                'Proxy-Authorization: Basic %s',
                base64_encode(Constants::XML_AUTH)
            ),
            'protocol_version' => '1.1',
            'proxy' => '89.122.180.178:46565'
        )
    );
    $stream = stream_context_create($set);

I'm not quite sure what I'm doing wrong.
If I comment out the `proxy` key i get a `403 Forbidden` Response as it should be.
If I comment in the `proxy` key I receive a `400 Bad Request` Response.

I'm not quite sure what I'm doing wrong. Can you help me out? I never did a communication through a proxy before with PHP.