anchor.diff:  -spec open(Port) -> {ok, Socket} | {error, Reason} when
         Port :: inet:port_number(),
         Socket :: socket(),
  -      Reason :: inet:posix().
  +      Reason :: system_limit | inet:posix().
   
   open(Port) -> 
       open(Port, []).
  
positive.code:               | {bind_to_device, binary()}
                | option(),
        Socket :: socket(),
        Reason :: inet:posix().
  
  open(Port, Opts0) ->
      {Mod, Opts} = inet:udp_module(Opts0),
  
negative.code:       Port :: inet:port_number(),
        AncData :: inet:ancillary_data(),
        Packet :: string() | binary(),
        Reason :: not_owner | timeout | inet:posix().
  
  recv(S,Len,Time) when is_port(S) ->
      case inet_db:lookup_socket(S) of
  