private static void setSecuredConfiguration(Configuration conf) {
    conf.set(CommonConfigurationKeys.HADOOP_SECURITY_AUTHENTICATION, "kerberos");
    conf.set(User.HBASE_SECURITY_CONF_KEY, "kerberos");
    conf.setBoolean(User.HBASE_SECURITY_AUTHORIZATION_CONF_KEY, true);
  }
Tests for HBASE-28321, where we have multiple server principals candidates for a rpc service.
<p>
Put here just because we need to visit some package private classes under this package.
hbase-server/src/test/java/org/apache/hadoop/hbase/ipc/TestMultipleServerPrincipalsIPC.java