code: function avgCpuLoad (span, cb) {
    if (typeof span !== 'number' || span < 0) span = 100
    var start = os.cpus()
  
    setTimeout(function avgCpuLoadCompare () {
      var totals = os.cpus().reduce(function (totals, end, i) {
        var busy = end.times.user + end.times.sys - start[i].times.user - start[i].times.sys
        totals.total += busy + end.times.idle - start[i].times.idle
        totals.busy += busy
        return totals
      }, {busy: 0, total: 0})
  
      cb(totals.busy / totals.total)
    }, span)
  }
docs: /*
  Generate the average CPU load across the time
  of your choosing.
  
  @func avgCpuLoad
  @param {number} milliseconds
  @param {function} callback
  @return {number} avg-load (1.0 = 100%)