anchor.diff:      <<_:Start/binary, Match:End/binary, _/binary>> = String,
       parse_matches(String, Rest, Acc ++ [Match]).
   
  -
   pval(X, Req) when element(1, Req) == http_req ->
       {Val, _} = cowboy_http_req:qs_val(X, Req),
       Val;
  
positive.code: reply(Key, <<"set">>, Proplist) ->
      Value = pval(<<"value">>, Proplist),
  
      case yasa:set(Key, Value) of
          {error, Reason} ->
              {500, [{<<"error">>, ?l2b(Reason)}]};
          Reply ->
  
negative.code:     Reply = to_range(Size, Period),
      Reply.
  
  to_int(Bin) when is_binary(Bin) ->
      list_to_integer(binary_to_list(Bin)).
  
  to_range(N, Period) ->
      [timestamp() - seconds_in(N, Period), timestamp()].
  
  