public function createCall(TokBoxApi $callApiObj, $persistent = 'false', $displayname = 'Guest')
 {
     $createCall = $callApiObj->createCall($displayname, $callApiObj->getJabberId(), "", $persistent);
     if (!$createCall) {
         throw new Exception("Unable to connect to " . API_Config::API_SERVER . ". Please check to make sure API calls are executing properly");
     }
     $createCallXml = simplexml_load_string($createCall, 'SimpleXMLElement', LIBXML_NOCDATA);
     return $createCallXml->createCall->callId;
 }
<?php

require_once '../SDK/TokBoxApi.php';
require_once '../Test_Config.php';
try {
    $apiObj = new TokBoxApi(API_Config::PARTNER_KEY, API_Config::PARTNER_SECRET);
    $apiObj->setJabberId(Test_Config::TEST_JABBERID);
    $apiObj->setSecret(Test_Config::TEST_ACCESS_SECRET);
    $result = $apiObj->createCall('A Name', $apiObj->getJabberId(), "", "false");
    header("content-type: text/xml");
    echo $result;
} catch (Exception $e) {
    echo $e->getMessage();
}