anchor.diff:  %% {@link ranch_transport} callback listen/1.
   %% @end
   %%--------------------------------------------------------------------
  --spec listen(ssl2:listen_opts()) -> {ok, ssl2:socket()} | {error, atom()}.
  +-spec listen([ssl2:option() | ssl2:ssl_option()]) ->
  +    {ok, ssl2:socket()} |{error, atom()}.
   listen(Opts) ->
       Port = proplists:get_value(port, Opts),
       ssl2:listen(Port, Opts).
  
positive.code: %% {@link ranch_transport} callback connect/4.
  %% @end
  %%--------------------------------------------------------------------
  -spec connect(string(), inet:port_number(), ssl2:listen_opts(), timeout()) ->
      {ok, ssl2:socket()} |
      {error, atom()}.
  connect(Host, Port, Opts, Timeout) ->
  
negative.code: %% {@link ranch_transport} callback setopts/2.
  %% @end
  %%--------------------------------------------------------------------
  -spec setopts(ssl2:socket(), [ssl2:option() | ssl2:ssl_option()]) ->
      ok | {error, atom()}.
  setopts(Socket, Opts) ->
      ssl2:setopts(Socket, Opts).
  
  