compose-derive
transform function into compose function
```rust
[compose]
pub fn MoviesScreen(movies: &Vec) {
Column(cx, |cx| {
for movie in movies {
cx.tag(movie.id, |cx| MovieOverview(cx, &movie));
}
});
}
// after expand
[track_caller]
pub fn MoviesScreen(cx: &mut compose_rt::Composer, movies: &Vec) {
Column(cx, |cx| {
for movie in movies {
cx.tag(movie.id, |cx| MovieOverview(cx, &movie));
}
});
}
```