public ServerBuilder gracefulShutdownTimeout(Duration quietPeriod, Duration timeout) {
        return gracefulShutdown(GracefulShutdown.builder()
                                                .quietPeriod(quietPeriod)
                                                .timeout(timeout)
                                                .build());
    }
Sets the amount of time to wait after calling {@link Server#stop()} for
requests to go away before actually shutting down.

@param quietPeriod the number of milliseconds to wait for active
                   requests to go end before shutting down. {@link Duration#ZERO} means
                   the server will stop right away without waiting.
@param timeout the amount of time to wait before shutting down the server regardless of active requests.
               This should be set to a time greater than {@code quietPeriod} to ensure the server
               shuts down even if there is a stuck request.
core/src/main/java/com/linecorp/armeria/server/ServerBuilder.java