@UnstableApi
    public VirtualHostBuilder contextHook(Supplier<? extends AutoCloseable> contextHook) {
        requireNonNull(contextHook, "contextHook");
        this.contextHook = mergeHooks(this.contextHook, contextHook);
        return this;
    }
Sets the {@link AutoCloseable} which will be called whenever this {@link RequestContext} is popped
from the {@link RequestContextStorage}.

@param contextHook the {@link Supplier} that provides the {@link AutoCloseable}
core/src/main/java/com/linecorp/armeria/server/VirtualHostBuilder.java