text: import { Observable as O } from '../rxjs'
  
  function display(msg) {
    if (!document.hasFocus()) {
      const notif = new Notification('Spark', { body: msg, tag: 'spark-msg', icon: 'notification.png' })
      notif.onclick = _ => window.focus()
    }
  }
  
  module.exports = msg$ => (
    O.from(msg$).subscribe(display)
  , O.empty()
  )
  