Kotlin delegate property that allows map key to be different than property name

custom_map_delegate.kt

import kotlin.properties.ReadWriteProperty
import kotlin.reflect.KProperty

fun <V> map(props: Props, key: String): ReadWriteProperty<Any?, V> {
    return object : ReadWriteProperty<Any?, V> {
        @Suppress("UNCHECKED_CAST")
        override fun getValue(thisRef: Any?, property: KProperty<*>): V = props[key]!! as V

        override fun setValue(thisRef: Any?, property: KProperty<*>, value: V) {
            props[key] = value
        }
    }
}