text: const util = require('util');
  const os = require('os');
  const exec = require('child_process').exec;
  const bleno = require('bleno');
  
  var Descriptor = bleno.Descriptor;
  var Characteristic = bleno.Characteristic;
  
  let SerialNumberCharacteristic = function() {
    SerialNumberCharacteristic.super_.call(this, {
      uuid: '2A25',
      properties: ['read'],
      value: new Buffer('1x1x1x'),
      descriptors: [
        new Descriptor({
          uuid: '2901',
          value: new Buffer('Serial Number')
        })
      ]
    });
  };
  util.inherits(SerialNumberCharacteristic, Characteristic);
  
  module.exports = SerialNumberCharacteristic;
  