protected function execute($request_method, $url, $parameters = null)
	{
		$extra_options = array(
			CURLOPT_HTTPAUTH => CURLAUTH_BASIC,
			CURLOPT_USERPWD => $this->_apiUsername . ':' . $this->_apiKey,
		);

		$url = 'https://www.browserstack.com/automate/' . $url;

		list($raw_results,) = $this->_curlService->execute($request_method, $url, $parameters, $extra_options);

		return json_decode($raw_results, true);
	}