Function collect_serial_content 

fn collect_serial_content(
    info: &AnimationInfo,
    path: &mut Vec<usize>,
    global_range: Range<f64>,
    serial_depth: usize,
    expanded: &HashSet<Vec<usize>>,
    clips: &mut Vec<VisibleClip>,
    bands: &mut Vec<SerialBand>,
    expanded_containers: &mut Vec<ExpandedContainer>,
)

Available on crate feature cmd-preview and non-target_family=wasm only.