KotlinKronicles-smarcasts.kt

class NEFT: Transaction ... // class NEFT extends Transaction
class IMPS: Transaction ... // class IMPS extends Transaction
class RTGS: Transaction ... // class RTGS extends Transaction

val transaction: Transaction = getCurrentTransaction()

// Now we don't know the type of transaction. It could be either of NEFT, IMPS or RTGS
// So we need to identify the type of trsaction and process it accordingly
when (transaction) {
    is NEFT -> transaction.processNEFT()
    is IMPS -> transaction.processIMPS()
    else -> println("No Processing required")
}