You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: lib.rs
    path of file: ./repos/seed/examples/intersection_observer/src
    
    the code of the file until where you have to start completion: use seed::{prelude::*, *};
use web_sys::{IntersectionObserver, IntersectionObserverEntry, IntersectionObserverInit};

fn init(_: Url, orders: &mut impl Orders<Msg>) -> Model {
    orders.after_next_render(|_| Msg::SetupObserver);
    Model {
        box_container: ElRef::new(),
        red
    
fn view_box_container(model: &Model) -> Node<Msg> {
    div![
        // don't allow VDOM to reuse the `div` for other elements (it would break observing)
        el_key(&"box-container"),
        el_ref(&model.box_container),
        style! {
            St::Height => vh(100),
        },
        view_blue_box(),
        view_red_box(&model.red_box),
        view_blue_box(),
    ]
}