code: @NonNull
      @CheckResult
      public static <T> LifecycleTransformer<T> bindActivity(@NonNull final Observable<ActivityEvent> lifecycle) {
          return bind(lifecycle, ACTIVITY_LIFECYCLE);
      }
docs: Binds the given source to an Activity lifecycle.
  <p>
  This helper automatically determines (based on the lifecycle sequence itself) when the source
  should stop emitting items. In the case that the lifecycle sequence is in the
  creation phase (CREATE, START, etc) it will choose the equivalent destructive phase (DESTROY,
  STOP, etc). If used in the destructive phase, the notifications will cease at the next event;
  for example, if used in PAUSE, it will unsubscribe in STOP.
  <p>
  Due to the differences between the Activity and Fragment lifecycles, this method should only
  be used for an Activity lifecycle.
  
  @param lifecycle the lifecycle sequence of an Activity
  @return a reusable {@link LifecycleTransformer} that unsubscribes the source during the Activity lifecycle