Function ("___setSoapHeaders") is not a valid method for this service

Question

Hello I am trying to work with the Google adWords API and just at the start I am running into an issue of having an "invalid method" even though I am following everything correctly (I believe) Here is my code:

ini_set("soap.wsdl_cache_enabled",0);

class adwords {

    protected $server = "###";
    protected $version = "###";
    protected $email = "###";
    protected $password = "###";
    protected $auth_key = "###";
    protected $dev_key = "###";
    protected $ua = "###";
    protected $client_id = ###;

    public function __construct() {
        $this->campaign_service();
    }

    public function campaign_service() {

        $service = "CampaignService";
        $options = array(
            'encoding' => 'utf-8',
            'features' => SOAP_SINGLE_ELEMENT_ARRAYS
        );
        $wsdl = "{$this->server}/{$this->version}/{$service}?wsdl";
        $namespace = "###";
        $header = array(
            'authToken' => $this->auth_key,
            'clientCustomerId' => $this->client_id,
            'userAgent' => $this->ua,
            'developerToken' => $this->dev_key
        );

        $client = new SoapClient($wsdl,$options);
        $headers = new SoapHeader($namespace,"RequestHeader",$header,false);
        $client->___setSoapHeaders($headers);

    }        
}

This is the error I get back:

PHP Fatal error: Uncaught SoapFault exception: [Client] Function ("___setSoapHeaders") is not a valid method for this service

Am I missing something? According to The PHP Manual this is a valid method. Further more I tried searching everything I could think of about this but cannot find anything. Any help is greatly appreciated! I am running PHP 5.3.3 by the way.

Answer 1

__setSoapHeaders, only two underscores, not three.