fn on_event( .. ) -> .. {
    if let Event::Window(_, window::Event::RedrawRequested(now)) = &event
    {
        let mut next_redraw: Option<window::RedrawRequest> = None;
        let mut removed_index = 0;    // Add this to keep track of the removed index

        self.instants.iter_mut().enumerate().for_each(
            |(index, maybe_instant)| {
                if let Some(instant) = maybe_instant.as_mut() {
                    let remaining =
                        Duration::from_secs(self.timeout_secs)
                            .saturating_sub(instant.elapsed());

                    if remaining == Duration::ZERO {
                        maybe_instant.take();
                        shell.publish((self.on_close)(index - removed_index));    // Adjust the toast to be removed, so the program wouldn't panic
                        removed_index += 1;    // Increment beacuse one toast was removed
                        next_redraw =
                            Some(window::RedrawRequest::NextFrame);
                    } else {
                        let redraw_at =
                            window::RedrawRequest::At(*now + remaining);
                        next_redraw = next_redraw
                            .map(|redraw| redraw.min(redraw_at))
                            .or(Some(redraw_at));
                    }
                }
            },
        );
        ..
}