code: public Object saveTransientState(FacesContext context)
      {
          TransientStateHelper helper = getTransientStateHelper(false);
  
          return (helper == null) ? null : helper.saveTransientState(context);
      }
docs: <p class="changed_added_2_1">For components that need to support
  the concept of transient state, this method will save any state
  that is known to be transient in nature.</p>
  
  @since 2.1