anchor.diff:  -spec connect(Socket, SockAddr) -> ok | {error, Reason} when
       Socket   :: socket(),
       SockAddr :: sockaddr(),
  -    Reason   :: reason().
  +    Reason   :: errcode() | closed.
   
   connect(Socket, SockAddr) ->
       connect(Socket, SockAddr, infinity).
  
positive.code:       Socket  :: socket(),
        MsgHdr  :: msghdr(),
        Flags   :: send_flags(),
        Reason  :: term();
               (Socket, MsgHdr, Timeout :: nowait) ->
                       ok |
                       {ok, Remaining} |
  
negative.code:       Flags      :: send_flags(),
        Timeout    :: timeout(),
        Remaining  :: erlang:iovec(),
        Reason     :: errcode() | closed | timeout.
  
  sendmsg(#socket{ref = SockRef} = Socket, MsgHdr, Flags, Timeout)
    when is_reference(SockRef), is_map(MsgHdr), is_list(Flags) ->
  