impl incr(key:string,default:num);

// We're testing that fallback will restart from Tick 1 after the last incr returns success.
// This covers a previous bug where fallback would forever repeat from the last child to return RUNNING.
root main {
    repeat(2) fallback {
        // Tick 1
        inverter incr("tick",0)
        // Tick 2
        inverter incr("tick",0)
        // Tick 3
        // Retry is used to force incr to return RUNNING the first time.
        retry(2) inverter incr("tick",0)
        // Tick 4
        incr("tick",0)
    }
}