@Deprecated
  default SaslClient createClient(Configuration conf, InetAddress serverAddr,
    SecurityInfo securityInfo, Token<? extends TokenIdentifier> token, boolean fallbackAllowed,
    Map<String, String> saslProps) throws IOException {
    throw new UnsupportedOperationException("should not be used any more");
  }
Creates the SASL client instance for this authentication method.
@deprecated Since 2.6.0. In our own code will not call this method any more, customized
            authentication method should implement
            {@link #createClient(Configuration, InetAddress, String, Token, boolean, Map)}
            instead. Will be removed in 4.0.0.
hbase-client/src/main/java/org/apache/hadoop/hbase/security/provider/SaslClientAuthenticationProvider.java