code: public void stop() {
          CompletableFuture.runAsync(() -> {
              try {
                  bootstrap.getInjector().getInstance(Server.class).stop();
              } catch (Exception ignore) {
                  // Ignore NPE. At this point the server REALLY should be possible to find
              }
              bootstrap.shutdown();
          });
      }
docs: Asynchronously shutdowns the server