@Immutable
open class Foo : Bar {
  open val abc: MyObject?
}

class NotFoo : Foo {
  override var abc: MyObject? = null
}

// I have a few constructors in Foo that I must supress the abc assignment warning
constructor(something: Double) : super(something) {
    @Supress("LeakingThis")
    this.abc = null
}