BananaApi.kt

class BananaApi {

    fun getBanana(id: String): Banana {
        return Banana(Color.GREEN, 0.5, id)
    }

    fun deleteBanana(id: String) {
        println("delete banana with id $id")
    }

    fun createBanana(banana: CreateBanana) {
        println("created $banana")
    }
}

data class Banana(val color: Color,
                  val price: Double,
                  val id: String,
                  val nickname: String? = null)

data class CreateBanana(
        val color: String,
        val price: Double)

data class ApiError(val error: String)

enum class Color {
    GREEN, YELLOW, BROWN
}