anchor.diff:      [erlang:trace(PidSpec, true, [call, {tracer, Pid} | TraceOpts])
        || PidSpec <- PidSpecs],
       lists:sum(Matches).
  +
  +
  +%%%%%%%%%%%%%%%%%%
  +%%% VALIDATION %%%
  +%%%%%%%%%%%%%%%%%%
   
   validate_opts(Opts) ->
       PidSpecs = validate_pid_specs(proplists:get_value(pid, Opts, all)),
  
positive.code:     Pid = setup(count_tracer, [Max]),
      trace_calls(MFAs, Pid, Opts).
  
  trace_calls(MFAs, Pid, Opts) ->
      {PidSpecs, TraceOpts, MatchOpts} = validate_opts(Opts),
      Matches = [begin
  
negative.code:         false ->
              ok
      end.
  
  %% Borrowed from dbg
  fun_to_ms(ShellFun) when is_function(ShellFun) ->
  