Kaba class Session ed

class Session extends Object
    var id: i32
    var playback: owned![Playback]
    var song: shared![Song]
    var storage: Storage&
    var view: AudioView&
    var win: Window&

    # constructors
    func mut __init__()

    # functions
    func create_child() -> xfer[Session]
    func mut create_signal_chain(name: string) -> shared![SignalChain]
    func e(msg: string)
    func i(msg: string)
    func mut load_signal_chain(filename: Path) -> shared[SignalChain]
    func mut remove_signal_chain(chain: SignalChain*)
    func sample_rate() -> i32
    func w(msg: string)