anchor.diff:  %% @throws not_found
   -spec event_log(match_stream:event()) -> ok.
   event_log(Event) ->
  -  make_call(write, {log, Event}).
  +  make_call(write_once, {log, Event}).
   
   %% @doc Returns match events
   -spec match_history(match_stream:match_id()) -> [match_stream:event()].
  
positive.code: %% Silently ignores the call if the match is not there
  -spec match_delete(match_stream:match_id()) -> ok.
  match_delete(MatchId) ->
    make_call(write, {delete, <<"match-", MatchId/binary>>}),
    make_call(write, {delete_events, MatchId}).
  
  %% @doc Deletes an user.
  %% Silently ignores the call if the user is not there
  
negative.code: %% @throws not_found
  -spec match_update(match_stream:match_id(), fun((match_stream:match()) -> match_stream:match())) -> ok.
  match_update(MatchId, UpdateFun) ->
    make_call(write_once, {update, <<"match-", MatchId/binary>>, UpdateFun}).
  
  %% @doc Updates an existing user
  %% @throws not_found
  