server.requestClientAuth();
server.enqueue(new MockResponse());

// Create a client certificate and a client that uses it.
HeldCertificate clientCertificate = new HeldCertificate.Builder()
    .commonName("ianmalcolm")
    .signedBy(rootCertificate)
    .build();
HandshakeCertificates clientCertificates = new HandshakeCertificates.Builder()
    .addTrustedCertificate(rootCertificate.certificate())