private void writeMessageToNIOSSLServer(SocketChannel clientChannel, NioSslEngine engine)
      throws IOException {
    System.out.println("client sending Hello World message to server");
    ByteBufferOutputStream bbos = new ByteBufferOutputStream(5000);
    DataOutputStream dos = new DataOutputStream(bbos);
    dos.writeUTF("Hello world");
    dos.flush();
    bbos.flush();
    ByteBuffer buffer = bbos.getContentBuffer();
    System.out.println(
        "client buffer position is " + buffer.position() + " and limit is " + buffer.limit());
    try (final ByteBufferSharing outputSharing = engine.wrap(buffer)) {
      ByteBuffer wrappedBuffer = outputSharing.getBuffer();
      System.out.println("client wrapped buffer position is " + wrappedBuffer.position()
          + " and limit is " + wrappedBuffer.limit());
      int bytesWritten = clientChannel.write(wrappedBuffer);
      System.out.println("client bytes written is " + bytesWritten);
    }
  }
see GEODE-4087. Geode should not establish a default SSLContext, preventing apps from using
different ssl settings via standard system properties. Since this test class sets these system
properties to establish a default context we merely need to perform an equality check between
the cluster's context and the default context and assert that they aren't the same.
geode-core/src/integrationTest/java/org/apache/geode/internal/net/SSLSocketIntegrationTest.java