anchor.diff:           send_promise/4,
            get_response/2,
            get_peer/1,
  +         get_peercert/1,
            get_streams/1,
            send_window_update/2,
            send_frame/2
  
positive.code:         {ok, _AddrPort}=OK ->
              {reply, OK, StateName, Conn}
      end;
  handle_sync_event(_E, _F, StateName,
                    #connection{}=Conn) ->
      {next_state, StateName, Conn}.
  
negative.code:     {ok, {inet:ip_address(), inet:port_number()}} | {error, term()}.
  get_peer(Pid) ->
      gen_fsm:sync_send_all_state_event(Pid, get_peer).
  
  -spec get_peercert(pid()) ->
      {ok, binary()} | {error, term()}.
  get_peercert(Pid) ->
      gen_fsm:sync_send_all_state_event(Pid, get_peercert).
  
  -spec is_push(pid()) -> boolean().
  is_push(Pid) ->
  