AfterUser2.kt

sealed class User(open val name: String) {
    data class Customer(
        override val name: String,
        val address: String,
        val phoneNumber: String
    ) : User(name)

    data class Store(
        override val name: String,
        val address: String,
        val businessNumber: String
    ) : User(name)

    data class Admin(
        override val name: String,
        val department: String
    ) : User(name)
}