POST with PHP file_get_contents to Google API

PHP_POST.gist

 $grant_type = 'refresh_token';
    $url = 'https://oauth2.googleapis.com/token';
    $data = array('refresh_token' => $refresh_token, 'client_id' => $client_id, 'client_secret' => $client_secret, 'redirect_uri' => $redirect_uri, 'grant_type' => $grant_type, 'scope' => $scope );

    // use key 'http' even if you send the request to https://...
    $options = array(
        'http' => array(
            'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
            'method'  => 'POST',
            'content' => http_build_query($data)
        )
    );
    $context  = stream_context_create($options);
    $strjson = file_get_contents($url, false, $context);