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: copy_component_recursive.rs
    path of file: ./repos/Ambient/crates/ecs/tests
    
    the code of the file until where you have to start completion: use ambient_ecs::{
    components, copy_component_recursive,
    generated::hierarchy::components::{children, parent},
    Entity, FrameEvent, System, World,
};

components!("test", {
    hello: f32,
    hello_recursive: f32,
});

#[test]
fn test_copy_component_recursive() {
    init_components();
    ambient_ecs::init_components();
    let mut world = World::new_unknown("test");

    let c = Entity::new().spawn(&mut world);
    let b 
    
fn test_copy_component_recursive() {
    init_components();
    ambient_ecs::init_components();
    let mut world = World::new_unknown("test");

    let c = Entity::new().spawn(&mut world);
    let b = Entity::new().with(parent(), c).spawn(&mut world);
    let a = Entity::new().with(parent(), b).spawn(&mut world);
    // no children
    let d = Entity::new().spawn(&mut world);

    world.add_component(a, children(), vec![b]).unwrap();
    world.add_component(b, children(), vec![c]).unwrap();
    world.add_component(a, hello_recursive(), 3.).unwrap();
    world.add_component(d, hello_recursive(), 4.).unwrap();

    let mut sys = copy_component_recursive("test", hello_recursive(), hello());
    sys.run(&mut world, &FrameEvent);
    assert_eq!(world.get(c, hello()).unwrap(), 3.);
    assert_eq!(world.get(d, hello()).unwrap(), 4.);

    world.next_frame();
    world.set(a, hello_recursive(), 2.).unwrap();
    world.set(d, hello_recursive(), 5.).unwrap();
    sys.run(&mut world, &FrameEvent);
    assert_eq!(world.get(c, hello()).unwrap(), 2.);
    assert_eq!(world.get(d, hello()).unwrap(), 5.);

    world.next_frame();
    world.remove_component(a, hello_recursive()).unwrap();
    world.remove_component(d, hello_recursive()).unwrap();
    sys.run(&mut world, &FrameEvent);
    assert!(!world.has_component(c, hello()));
    assert!(!world.has_component(d, hello()));
}