RFR: 8283706: Add final or sealed modifier to appropriate javax.swing API classes

[Alexey Ivanov]

On Sat, 2 Apr 2022 23:21:03 GMT, Phil Race <prr at openjdk.org> wrote:

> Update Swing classes to use JEP 409 sealed and non-sealed modifiers and add the final modifier where appropriate.
> 
> jtreg tests and JCK API tests pass
> 
> CSR for review here : https://bugs.openjdk.java.net/browse/JDK-8284214

Marked as reviewed by aivanov (Reviewer).

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

PR: https://git.openjdk.java.net/jdk/pull/8082