anchor.diff:          V when V =:= undefined; V =:= default ->
               application:get_env(dalmatiner_db, r)
       end.
  -
  -get_n_opt(Opts) ->
  -    case proplists:get_value(n, Opts) of
  -        undefined ->
  -            application:get_env(dalmatiner_db, n);
  -        Value ->
  -            {ok, Value}
  -    end.
  
positive.code:             {ok, true}
      end.
  
  get_r_opt(Opts) ->
      N = get_n_opt(Opts),
      case proplists:get_value(r, Opts) of
          n ->
              N;
  
negative.code: 
  init([ReqId, {VNode, System}, Op, From, Entity, Val, Opts]) ->
      {ok, RR} = get_rr_opt(Opts),
      {ok, N} = get_n_opt(Opts),
      {ok, R} = get_r_opt(Opts, N),
      Compression = application:get_env(dalmatiner_db,
                                        metric_transport_compression, snappy),
  
  