public function test_signature()
 {
     // apiKey and secretKey from example code from official API reference
     // @see http://download.cloud.com/releases/2.2.0/api_2.2.4/user/2.2api_examplecode_details.html
     $apiKey = "miVr6X7u6bN_sdahOBpjNejPgEsT35eXq-jB8CG20YI3yaxXcgpyuaIRmFI_EJTVwZ0nUkkJbPmY3y2bciKwFQ";
     $secretKey = "AdpTvsQMZwv9MNvfqDcQhWSL9pHQvq7z13CFP2SU1iToDkkM3d8iZciWEKsGREhMtV9yLVMxmbbJJgrXo8O5jg";
     $queryString = "apikey=" . strtolower($apiKey) . "&command=listvirtualmachines&response=json";
     $cloudstack = new BaseCloudStackClient("http://foo", $apiKey, $secretKey);
     $this->assertEquals($cloudstack->getSignature($queryString), "dPQ94TY7lQAR6tjOVt9smq3xaSY%3D");
 }