State.kt

enum class Navigation {
    ITEMS_LIST,
    EDIT_ITEM
}

data class ItemsListScreen(
        val items: List<Item> = emptyList())

data class EditItemScreen(val currentItem: Item = Item())

data class State(
        val itemsListScreen: ItemsListScreen = ItemsListScreen(),
        val editItemScreen: EditItemScreen = EditItemScreen(),
        val navigation: Navigation = Navigation.ITEMS_LIST)