anchor.diff:  
   decode_extensions(<<?UINT16(?SUPPORTED_VERSIONS_EXT), ?UINT16(Len),
                          ExtData:Len/binary, Rest/binary>>, Version, MessageType, Acc) when Len > 2 ->
  -    <<?UINT16(_),Versions/binary>> = ExtData,
  +    <<?BYTE(_),Versions/binary>> = ExtData,
       decode_extensions(Rest, Version, MessageType,
                         Acc#{client_hello_versions =>
                                  #client_hello_versions{
  
positive.code: 		       ?BYTE(SID_length), Session_ID:SID_length/binary,
  		       Cipher_suite:2/binary, ?BYTE(Comp_method),
  		       ?UINT16(ExtLen), Extensions:ExtLen/binary>>) ->
  
      HelloExtensions = decode_hello_extensions(Extensions, Version, {Major, Minor}, server_hello),
  
      #server_hello{
  
negative.code: encode_extensions([#client_hello_versions{versions = Versions0} | Rest], Acc) ->
      Versions = encode_versions(Versions0),
      VerLen = byte_size(Versions),
      Len = VerLen + 1,
      encode_extensions(Rest, <<?UINT16(?SUPPORTED_VERSIONS_EXT),
                                ?UINT16(Len), ?BYTE(VerLen), Versions/binary, Acc/binary>>);
  encode_extensions([#server_hello_selected_version{selected_version = Version0} | Rest], Acc) ->
      Version = encode_versions([Version0]),
      Len = byte_size(Version), %% 2
  