PersistentReusableContainer.swift

let container = Container<CalendarKeys>()

let event1 = EventItem(date: Date(), title: "title1", description: "description1")
container.add(event1, key: .homeEvents)
let event2 = EventItem(date: Date(), title: "title2", description: "description2")
container.add(event2, key: .workEvents)
let note1 = NoteItem(text: "text3")
container.add(note1, key: .notes)

let homeEvents: [EventItem] = container.items(forKey: .homeEvents)
let workEvents: [EventItem] = container.items(forKey: .workEvents)
let notes: [NoteItem] = container.items(forKey: .notes)

let url = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent("Test")
do {
    try container.write(to: url)
}
catch {
    print(error as NSError)
}

do {
    let restoredContainer = try Container<CalendarKeys>(contentsOfURL: url)
    let homeEvents: [EventItem] = restoredContainer.items(forKey: .homeEvents)
    let workEvents: [EventItem] = restoredContainer.items(forKey: .workEvents)
    let notes: [NoteItem] = restoredContainer.items(forKey: .notes)
    print("Home events: ", homeEvents)
    print("Work events: ", workEvents)
    print("Notes: ", notes)
}
catch {
    print(error as NSError)
}