patternmatching.cs

static State Request(this State state, Transition transition) =>
(state, transition) match
(
    case (State.Running, Transition.Suspend): State.Suspended
    case (State.Suspended, Transition.Resume): State.Running
    case (State.Suspended, Transition.Terminate): State.NotRunning
    case (State.NotRunning, Transition.Activate): State.Running
    case *: throw new InvalidOperationException()
);