class ChainedProperty<Main, Fallback>(
    val main: Main,
    val fallback: Fallback
)

operator fun <R, V : Any> ChainedProperty<ReadOnlyProperty<R, V?>, ReadOnlyProperty<R, V>>.getValue(thisRef: R, property: KProperty<*>): V
operator fun <R, V : Any> ChainedProperty<ReadOnlyProperty<R, V?>, ReadWriteProperty<R, V>>.getValue(thisRef: R, property: KProperty<*>): V
operator fun <R, V : Any> ChainedProperty<ReadWriteProperty<R, V?>, ReadOnlyProperty<R, V>>.getValue(thisRef: R, property: KProperty<*>): V
operator fun <R, V : Any> ChainedProperty<ReadWriteProperty<R, V?>, ReadWriteProperty<R, V>>.getValue(thisRef: R, property: KProperty<*>): V
operator fun <R, V> ChainedProperty<ReadWriteProperty<R, V>, *>.setValue(thisRef: R, property: KProperty<*>, value: V)