This tests behavior on the process "CreateConferenceTicketsForWebinarCustomers".
It's possible to create a working test that looks like the "minimum possible" example. But the "actual" example has additional information that supplements the test. The null parameter with default values pattern is not new.
In this case, the named parameters improve the comprehensibility of the tests.
This is one of hundreds of tests that I've used this technique for. When testing various paths through the same process, being able to swap values in then given/when/then steps can be really beautiful.