code: function sliceDevices(devices, chunkSize) {
    let chunkDevices = [];
    while (devices.length > 0) {
      chunkDevices.push(devices.splice(0, chunkSize));
    }
    return chunkDevices;
  }
docs: Slice a list of devices to several list of devices with fixed chunk size.
  @param {Array} devices An array of devices
  @param {Number} chunkSize The size of the a chunk
  @returns {Array} An array which contaisn several arries of devices with fixed chunk size