anchor.diff:      #state{handle = Handle, level = LogLevel} = State) when Level =< LogLevel ->
       nt_eventlog:report_event(Handle, Level, lists:flatten([Location, Message])),
       {ok, State};
  -handle_event({log, Message}, #state{handle = Handle, level=Level} = State) ->
  +handle_event({log, Message}, #state{handle = Handle, level = Level, formatter = Formatter, format_config = FormatConfig} = State) ->
       case lager_util:is_loggable(Message, Level, ?MODULE) of
           true ->
  -            nt_eventlog:report_event(Handle, Level, lager_default_formatter:format(Message, ?DEFAULT_FORMAT)),
  +            nt_eventlog:report_event(Handle, Level, Formatter:format(Message, FormatConfig)),
               {ok, State};
           false ->
               {ok, State}
  
positive.code: -export([init/1, handle_call/2, handle_event/2, handle_info/2, terminate/2,
          code_change/3]).
  
  -record(state, {handle, level}).
  
  -define(DEFAULT_FORMAT, [{pid, ""}, {module, [{pid, ["@"], ""}, module, {function, [":", function], ""}, {line, [":",line], ""}], ""}, " ", message]).
  -include_lib("lager/include/lager.hrl").
  
  %% @private
  init([Source, Level]) ->
      case nt_eventlog:register_event_source(Source) of
          {ok, Handle} ->
              {ok, #state{level=lager_util:level_to_num(Level),
                          handle = Handle}};
          Error ->
              Error
      end.
  
negative.code:     nt_eventlog:deregister_event_source(Handle).
  
  %% @private
  code_change("0.9.0", {state, Handle, Level}, _Extra) ->
      {ok, #state{handle = Handle, level = Level, format_config = lager_default_formatter, format_config = ?DEFAULT_FORMAT }};
  code_change(_OldVsn, State, _Extra) ->
      {ok, State}.
  