RFR: 8216507: StyleablePropertyFactory: example in class javadoc does not compile [v2]

[Karthik P K]

On Fri, 23 Dec 2022 17:01:14 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> I will check this and update here
>
> Do you think it's worth doing this as a unit test?

I think it is good to add unit test to test the example code. Only thing I'm looking at is that if the example changes in future, we need to make sure that corresponding `MyButton` class is updated in unit test. 
Since the example code might not change frequently, we can add unit test.

-------------

PR: https://git.openjdk.org/jfx/pull/983