@Test
  public void testClientAuth() throws Exception {
    stub.echo(null, TestProtos.EchoRequestProto.newBuilder().setMessage("hello world").build());
  }
Tests for client-side mTLS focusing on client hostname verification in the case when client and
server are on different hosts. We try to simulate this behaviour by querying the hostname with
<p>
InetAddress.getLocalHost()
</p>
Certificates are generated with the hostname in Subject Alternative Names, server binds
non-localhost interface and client connects via remote IP address. Parameter is set to verify
both TLS/plaintext and TLS-only cases.
hbase-server/src/test/java/org/apache/hadoop/hbase/security/TestMutualTlsClientSideNonLocalhost.java