public ServerListenerBuilder whenStopping(Consumer<? super Server> consumer) {
        serverStoppingCallbacks.add(requireNonNull(consumer, "consumer"));
        return this;
    }
Adds a {@link Consumer} invoked when the {@link Server} is stopping.

@see ServerListener#serverStopping(Server)
core/src/main/java/com/linecorp/armeria/server/ServerListenerBuilder.java