bananasService.kt

class BananaService {
    fun getBanana(id: String): Banana {
        return Banana(Color.YELLOW, 0.5, id)
    }
    fun createBanana(banana: CreateBanana) : Banana  {
        return Banana(Color.GREEN, 0.5, "random id")
    }
}

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,
	val nickname: String? = null
)

data class ApiError(val error: String)

enum class Color {
    GREEN, YELLOW, BROWN
}