////// KINDS

    private fun ConeKotlinType.toConstantValueKind(): ConstantValueKind<*>? =
        when (this) {
            is ConeErrorType -> null
            is ConeLookupTagBasedType -> lookupTag.name.asString().toConstantValueKind()
            is ConeFlexibleType -> upperBound.toConstantValueKind()
            is ConeCapturedType -> lowerType?.toConstantValueKind() ?: constructor.supertypes!!.first().toConstantValueKind()