anchor.diff:  
   -module(async).
   
  +-include("ns_common.hrl").
  +
   -export([start/1, start_many/2,
            abort/1, abort_many/1,
            send/2,
  
positive.code:             Result = async_loop_handle_result(Result0),
  
              unlink(Child),
              receive
                  {'EXIT', Child, _} -> ok
              after
                  0 -> ok
              end,
  
              async_loop_with_result(ParentMRef, Result);
          {'$async_msg', Msg} ->
  
negative.code: drop_extra_resps(PidMRefs) ->
      lists:foreach(
        fun ({_, MRef}) ->
                ?flush({MRef, _})
        end, PidMRefs).
  
  reply({Pid, Tag}, Reply) ->
  