The intention is to have a new subsection after code of UserTransaction Code Example that would show the same thing but not for EJB remoting but for IIOP call. Basically there is two (main) ways how to call an ejb and propagate a transaction with this call - ejb remoting which is already covered in this section and iiop call that is currently covered nowhere. So my intention is to have here a example how to start a transaction on client and that transaction will be propagated to server.

Here should be aimed on transaction started on client propagated to server via iiop call.
Example of how to start a transaction on client and propagate (which is transparent process to a user) to a server is as mentioned in quickstarts: https://github.com/wildfly/wildfly/blob/master/testsuite/integration/iiop/src/test/java/org/jboss/as/test/iiop/client/. Having this being set is a bit more complex process. You can check the testcase
https://github.com/wildfly/wildfly/blob/master/testsuite/integration/iiop/src/test/java/org/jboss/as/test/iiop/client/IIOPTransactionPropagationTestCase.java#L114
The @Test itself uses Util class and do first preparation in @BeforeClass and then uses calls like commit and rolled back called to Util class again. My idea was to summarize this testcase into documentation with some description.