UFile (package = ) [public final class Demo {...]
    UClass (name = Demo) [public final class Demo {...}]
        UField (name = foo) [private final var foo: error.NonExistentClass = [!] UnknownKotlinExpression (DOT_QUALIFIED_EXPRESSION)]
            [!] UnknownKotlinExpression (DOT_QUALIFIED_EXPRESSION) [[!] UnknownKotlinExpression (DOT_QUALIFIED_EXPRESSION)] = Undetermined
        UMethod (name = Demo) [public fun Demo() = UastEmptyExpression]
        UMethod (name = getFoo) [public final fun getFoo() : error.NonExistentClass = UastEmptyExpression]