lib/mock.js
function getUnscheduler () {
  // TODO: Create a map of IDs if the schedules array gets large.
  return function (id) {
    for (var i = 0, l = schedules.length; i < l; i++) {
      var schedule = schedules[i]
      if (schedule.id === id) {
        schedules.splice(i, 1)
        break
      }
    }
  }
}
function getUnscheduler () {
  // TODO: Create a map of IDs if the schedules array gets large.
  return function (id) {
    for (var i = 0, l = schedules.length; i < l; i++) {
      var schedule = schedules[i]
      if (schedule.id === id) {
        schedules.splice(i, 1)
        break
      }
    }
  }
}
The `getUnscheduler` returns mocks for `clearTimeout` and `clearInterval`.