Add support for record classes

[espertus]

The record keyword, added in Java 14, is not supported. I would be willing to try adding it if you don't want to do it yourself.

[shuzijun]

I'm not familiar with this keyword, and contributions are welcome.

[espertus]

Thanks! I'm working on adding them. I usually use JUnit for testing. Would you prefer that I add my tests without adding any dependencies or with JUnit?