anchor.diff:  %%%===================================================================
   %%% Internal Functions
   %%%===================================================================
  -
  +-spec merge(state(), [E]) -> E.
   merge(#state{system = event}, Events) ->
       merge_events(Events);
   merge(#state{system = metric}, Metrics) ->
  
positive.code:                 num_r=0,
                  size,
                  timeout=?DEFAULT_TIMEOUT,
                  type = metric,
                  val,
                  vnode,
                  system,
  
negative.code: 
  -type partition() :: chash:index_as_int().
  -type reply_src() :: {partition(), term()}.
  -type metric_element() :: {non_neg_integer(), binary()}.
  %%-type metric_reply() :: {partition(), metric_element()}.
  
  -record(state, {req_id,
                  from,
  