anchor.diff:       {group, ecdsa}].
   
   tests() ->
  -    [tls13_client_tls12_server,
  +    [%%tls13_client_tls12_server, %% Not testable with current openssl s_client
        %%tls13_client_with_ext_tls12_server,
        tls12_client_tls13_server].
       
  
positive.code: %% Test Cases --------------------------------------------------------
  %%--------------------------------------------------------------------
  
  tls13_client_tls12_server() ->
      [{doc,"Test that a TLS 1.3 client can connect to a TLS 1.2 server."}].
  
  
negative.code:                 
              
  %%     ssl_test_lib:basic_test(ClientOpts, ServerOpts, Config).
  
  
  %% TODO: wrong version of TLS is configured for the client
  tls12_client_tls13_server() ->
      [{doc,"Test that a TLS 1.2 client can connect to a TLS 1.3 server."}].
  
  tls12_client_tls13_server(Config) when is_list(Config) ->
      ClientOpts = [{versions,
                     ['tlsv1.1', 'tlsv1.2']} | ssl_test_lib:ssl_options(client_cert_opts, Config)],
      ServerOpts =  [{versions,
  