protected function createUrl($coverage_script_url, $test_id)
	{
		if ( !$coverage_script_url || !$test_id ) {
			throw new \InvalidArgumentException('Both Coverage script URL and Test ID must be filled in');
		}

		$query_string = array(
			'rct_mode' => 'output',
			RemoteCoverageTool::TEST_ID_VARIABLE => $test_id,
		);

		$url = $coverage_script_url;
		$url .= strpos($url, '?') === false ? '?' : '&';
		$url .= http_build_query($query_string);

		return $url;
	}