class Country(private var info: Map<String, Any>) {
    @Suppress("UNCHECKED_CAST")
    operator fun <T> get(key: String): T? {
        return info[key] as T?
    }
}

val france = Country(mapOf(
        "Name" to "France", 
        "Population" to 66_991_000))

val name: String? = france["Name"]
//name is "France"
val population: Int? = france["Population"]
//population is 66991000

println("name is $name")
println("population is $population")