in firestore/FirestoreExample/RestaurantsTableViewController.swift [24:38]
func priceString(from price: Int) -> String {
let priceText: String
switch price {
case 1:
priceText = "$"
case 2:
priceText = "$$"
case 3:
priceText = "$$$"
case _:
fatalError("price must be between one and three")
}
return priceText
}