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: event_tests.rs
    path of file: ./repos/sauron/tests
    
    the code of the file until where you have to start completion: #![deny(warnings)]
use sauron::{html::attrib
    
fn remove_event_from_truncated_children() {
    console_log::init_with_level(log::Level::Trace).ok();
    let cb = on_click(|_| log::trace!("Clicked here"));
    let old: Node<()> = div(
        vec![],
        vec![
            button(vec![cb.clone()], vec![]),
            button(vec![cb.clone()], vec![]),
            button(vec![cb.clone()], vec![]),
            button(vec![cb.clone()], vec![]),
            button(vec![cb.clone()], vec![]),
        ],
    );

    let new: Node<()> = div(vec![], vec![button(vec![cb.clone()], vec![])]);

    let mut simple_program = simple_program();
    let diff = diff(&old, &new);
    log::debug!("{:#?}", diff);
    assert_eq!(
        diff,
        vec![
            Patch::remove_node(Some(&"button"), TreePath::new(vec![1]),),
            Patch::remove_node(Some(&"button"), TreePath::new(vec![2]),),
            Patch::remove_node(Some(&"button"), TreePath::new(vec![3]),),
            Patch::remove_node(Some(&"button"), TreePath::new(vec![4]),),
        ],
    );

    simple_program
        .update_dom_with_vdom(old, None)
        .expect("must update dom");
    assert_eq!(
        simple_program.node_closures.borrow().len(),
        5,
        "There should be 5 events attached to the DomUpdater"
    );
    simple_program
        .update_dom_with_vdom(new, None)
        .expect("must not error");

    assert_eq!(
        simple_program.node_closures.borrow().len(),
        1,
        "There should only be 1 left after the truncate"
    );
}