Friends, I have a question . . . so mutable data classes are very usable in Java. And that is great. However, immutable data classes (all vals) are pretty much unusable in java, because the .copy(oneParamToChange: newValue) does not work in java due to the lack of named arguments. So if you have an immutable value object with say 7 different things, it's pretty much impossible to change (i.e. create a new object having just that thing changed) just one of those things from java.