Why Room entities don't work with immutable properties in Android

Question

I have been exploring Room database object mapping library and I figured something weird.

An entity data model cannot have immutable properties, as this answer sugge

Answer 1

I believe that the issue stems from certain fields which can not be constructor parameters. From the Javadoc of the @Relation annotation:

Note that the @Relation annotated field cannot be a constructor parameter, it must be public or have a public setter.

As a workaround, I had a private constructor parameter _myRelationProperty and a public field:

val myRelationProperty: List get() = _myRelationProperty