code: protected StateHelper getStateHelper(boolean create)
      {
          if (_stateHelper != null)
          {
              return _stateHelper;
          }
          if (create)
          {
              _stateHelper = new _DeltaStateHelper(this);
          }
          return _stateHelper;
      }
docs: returns a delta state saving enabled state helper
  for the current component
  @param create if true a state helper is created if not already existing
  @return an implementation of the StateHelper interface or null if none exists and create is set to false