code: @Override
      public StateManagementStrategy getStateManagementStrategy(FacesContext context, String viewId)
      {
          // Use partial state saving strategy only if javax.faces.PARTIAL_STATE_SAVING is "true" and
          // the current view is not on javax.faces.FULL_STATE_SAVING_VIEW_IDS.
          if (_partialStateSaving && _stateMgmtStrategy == null)
          {
              _stateMgmtStrategy = new DefaultFaceletsStateManagementStrategy(context);
          }
  
          return _usePartialStateSavingOnThisView(viewId) ? _stateMgmtStrategy : null;
      }
docs: {@inheritDoc}