// lets create a calendar
let my_calendar = Calendar::new()
    .name("example calendar")
    .push(
        // add an event
        Event::new()
            .summary("test event")
            .description("here I have something really important to do")
            .starts(Utc::now())
            .class(Class::Confidential)
            .ends(Utc::now() + Duration::days(1))
            .append_property(
                Property::new("TEST", "FOOBAR")
                    .add_parameter("IMPORTANCE", "very")
                    .add_parameter("DUE", "tomorrow")
                    .done(),
            )
            .done(),
    )
    .push(
        // add a todo
        Todo::new()
            .summary("groceries")
            .description("Buy some milk")
            .done(),
    )
    .push(
        // add an all-day event
        Event::new()
            .all_day(NaiveDate::from_ymd_opt(2016, 3, 15).unwrap())
            .summary("My Birthday")
            .description("Hey, I'm gonna have a party\nBYOB: Bring your own beer.\nHendrik")
            .done(),
    )
    .push(
        // local event with timezone
        Event::new()
            .starts(CalendarDateTime::from_ymd_hm_tzid(2023, 3, 15, 18, 45, Berlin).unwrap())
            .summary("Birthday Party")
            .description("I'm gonna have a party\nBYOB: Bring your own beer.\nHendrik")
            .done(),
    )
    .done();

println!("{}", my_calendar);

//... continue from previous example

let parsed_calendar = my_calendar.parse::<Calendar>()?;