public SaslServerAuthenticationProvider selectProvider(byte authByte) {
    return providers.get(Byte.valueOf(authByte));
  }
Selects the appropriate SaslServerAuthenticationProvider from those available. If there is no
matching provider for the given {@code authByte}, this method will return null.
hbase-server/src/main/java/org/apache/hadoop/hbase/security/provider/SaslServerAuthenticationProviders.java