text: module.exports = function mbps (bytes, seconds) {
      var speed = seconds ? bytes * 8 / seconds : 0
      var units = [' bps', ' kbps', ' Mbps', ' Gbps', ' Tbps', 'Pbps', 'Ebps', 'Zbps', 'Ybps']
      var unitNum = 0
      while (speed > 1024) {
          speed = speed / 1024
          unitNum++
      }
      return Math.max(speed, 0.1).toFixed(1) + units[unitNum]
  }
  