I think the failure is not related, so setting back to RTBC. I am just addres...

I think the failure is not related, so setting back to RTBC. I am just addressing the minor change in #38.2.

Can we put the handler settings into a variable called $handler_settings, just for easier readability?

We need to have an if check to see if the key is set, which kind of makes it harder to understand, even if the later code is slightly easier to read. I thought about different ways to resolve this but nothing stood out as simple and easy.

We should be using assertSame() for PHPUnit kernel tests, not assertIdentical().

There are other assertIdentical() in the same test case which makes using assertSame() slightly confusing. I think we should address that separately.