/** * Configure SDK to run against WePay's staging servers * @param string $client_id Your application's client id * @param string $client_secret Your application's client secret * @return void * @throws RuntimeException */ public static function useStaging($client_id, $client_secret, $api_version = null) { if (self::$production !== null) { throw new RuntimeException('API mode has already been set.'); } self::$production = false; self::$client_id = $client_id; self::$client_secret = $client_secret; self::$api_version = $api_version; }