code: @NonNull @UiThread
      public static Router attachRouter(@NonNull Activity activity, @NonNull ViewGroup container, @Nullable Bundle savedInstanceState) {
          ThreadUtils.ensureMainThread();
  
          LifecycleHandler lifecycleHandler = LifecycleHandler.install(activity);
  
          Router router = lifecycleHandler.getRouter(container, savedInstanceState);
          router.rebindIfNeeded();
  
          return router;
      }
docs: Conductor will create a {@link Router} that has been initialized for your Activity and containing ViewGroup.
  If an existing {@link Router} is already associated with this Activity/ViewGroup pair, either in memory
  or in the savedInstanceState, that router will be used and rebound instead of creating a new one with
  an empty backstack.
  
  @param activity The Activity that will host the {@link Router} being attached.
  @param container The ViewGroup in which the {@link Router}'s {@link Controller} views will be hosted
  @param savedInstanceState The savedInstanceState passed into the hosting Activity's onCreate method. Used
  for restoring the Router's state if possible.
  @return A fully configured {@link Router} instance for use with this Activity/ViewGroup pair.