anchor.diff:      lists:filter(fun (E) -> is_atom(E) andalso E =/= unassigned end,
                    ClientSignatureSchemes).
   
  -get_certificate_authorites(#certificate_authorities{authorities = Auths}) ->
  +get_certificate_authorities(#certificate_authorities{authorities = Auths}) ->
       Auths;
  -get_certificate_authorites(undefined) ->
  +get_certificate_authorities(undefined) ->
       [].
   
   get_supported_groups(undefined = Groups) ->
  
positive.code:                        maps:get(signature_algs, Extensions, undefined)),
      ServerSignAlgsCert = get_signature_scheme_list(
                             maps:get(signature_algs_cert, Extensions, undefined)),
      CertAuths = get_certificate_authorites(maps:get(certificate_authorities, Extensions, undefined)),
  
      CertKeyPairs = ssl_certificate:available_cert_key_pairs(CertKeyAlts, Version),
      Session = select_client_cert_key_pair(Session0, CertKeyPairs,
  
negative.code:             select_client_cert_key_pair(Session0, Rest, ServerSignAlgsCert, ServerSignAlgsCert, ClientSignAlgs,
                                          CertDbHandle, CertDbRef, CertAuths)
      end.
  