code: public void restoreTransientState(FacesContext context, Object state)
      {
          boolean forceCreate = (state != null);
          TransientStateHelper helper = getTransientStateHelper(forceCreate);
  
          if (helper != null) {
              helper.restoreTransientState(context, state);
          }
      }
docs: <p class="changed_added_2_1">For components that need to support
  the concept of transient state, this method will restore any
  state saved on a prior call to {@link #saveTransientState}.</p>
  
  @since 2.1