private Configuration getClientConf() {
    Configuration conf = new Configuration(CONF);
    conf.set(RpcClientFactory.CUSTOM_RPC_CLIENT_IMPL_CONF_KEY, rpcClientImpl);
    return conf;
  }
Custom provider which can select our custom provider, amongst other tokens which may be
available.
hbase-server/src/test/java/org/apache/hadoop/hbase/security/provider/CustomSaslAuthenticationProviderTestBase.java