Kaba struct SongSelection ed

struct SongSelection
    var range_raw: Range

    # constructors
    func mut __init__(range_raw: Range)

    # functions
    func has_bar(b: Bar) -> bool
    func has_layer(t: TrackLayer) -> bool
    func has_marker(m: TrackMarker) -> bool
    func has_note(n: MidiNote) -> bool
    func has_track(t: Track) -> bool
    func range() -> Range

    # operators
    func mut __assign__(other: SongSelection) # SongSelection = SongSelection