Node-taglib read AudioProperties

I try to read AudioProperties (bitrate) with Node-taglib , here's my code :

var taglib = require('taglib');

taglib.tag("./love-me-like-you-do.mp3", function(err, tag, audioProperties) {
    console.log(tag);
    console.log(audioProperties);
});

here's my output :

{ genre: null,
  year: 0,
  track: 0,
  artist: 'Love Me Like You Do - Ellie Goulding',
  comment: null,
  album: 'Love Me Like You Do - Ellie Goulding',
  title: 'Love Me Like You Do - Ellie Goulding' }
undefined

As you can see there is undefined for audioProperties

I be appreciated if tell me where i am wrong.