text: 
  
  import { periodic, observe, just }             from 'most'
  import { createAnimationTrigger }              from '../../drivers/createAnimationTrigger.js'
  import { simpleClock }                         from './simpleClock.js'
  
  const trigger$ = createAnimationTrigger()()
  
  const control$ = periodic(1000, true).loop(
    (s,x) => {
      let v = s ? "Start" : "Stop"
      return { seed: !s , value: v }
    }, true )
    // give the app time to settle down
    .delay(500)
    // Emit three start/stop pairs. Should emit triggers after "Start" and not emit after "Stop"
    .take(6)
    // Terminate the clock.
    .concat( just("End") )
    // Try to start it up again.  Should fail.
    .concat( just("Start").delay(500) )
  
  //trigger$.observe( x => console.log("Trigger = " + x))
  control$.observe( x => console.log("Control = " + x))
  
  const clock$ = simpleClock(trigger$, control$)
  
  clock$.observe( x => console.log(x))
  