code: @Override
      public void markInitialState() {
          super.markInitialState();
  
          if (listeners != null) {
              listeners.markInitialState();
          }
          if (listenersByEventClass != null) {
              for (List<SystemEventListener> listener : listenersByEventClass.values()) {
                  if (listener instanceof PartialStateHolder) {
                      ((PartialStateHolder) listener).markInitialState();
                  }
              }
          }
          if (behaviors != null) {
              for (Entry<String, List<ClientBehavior>> entry : behaviors.entrySet()) {
                  for (ClientBehavior behavior : entry.getValue()) {
                      if (behavior instanceof PartialStateHolder) {
                          ((PartialStateHolder) behavior).markInitialState();
                      }
                  }
              }
          }
      }
docs: <p class="changed_added_2_0">For each of the attached objects on
  this instance that implement {@link PartialStateHolder}, call
  {@link PartialStateHolder#markInitialState} on the attached object.</p>
  @since 2.0