anchor.diff:  
   notify1(error, Node, NumOfErrors, Thresholds) when NumOfErrors >= Thresholds ->
       State = ?STATE_STOP,
  -    Cause = "could not modify storage status",
  +    Cause = ?ERROR_COULD_NOT_MODIFY_STORAGE_STATE,
   
       case leo_manager_mnesia:update_storage_node_status(
              update_state, #node_state{node  = Node,
  
positive.code:     case leo_manager_mnesia:update_storage_node_status(increment_error, #node_state{node = Node}) of
          ok ->
              ok;
          _ ->
              {error, "could not modify storage status"}
      end.
  
  notify2(error, Node, Clock, State) ->
  
negative.code:                             notify1(error, Node, NumOfErrors, Size)
                      end;
                  _ ->
                      {error, ?ERROR_COULD_NOT_MODIFY_STORAGE_STATE}
              end;
          _Error ->
              {error, ?ERROR_COULD_NOT_MODIFY_STORAGE_STATE}
      end;
  
  notify(synchronized, VNodeId, Node) ->
  