code: function(str, $parent) {
  	if (!str) {
  		return 0;
  	}
  
  	if (!Selectize.$testInput) {
  		Selectize.$testInput = $('<span />').css({
  			position: 'absolute',
  			top: -99999,
  			left: -99999,
  			width: 'auto',
  			padding: 0,
  			whiteSpace: 'pre'
  		}).appendTo('body');
  	}
  
  	Selectize.$testInput.text(str);
  
  	transferStyles($parent, Selectize.$testInput, [
  		'letterSpacing',
  		'fontSize',
  		'fontFamily',
  		'fontWeight',
  		'textTransform'
  	]);
  
  	return Selectize.$testInput.width();
  }
docs: Measures the width of a string within a
  parent element (in pixels).
  
  @param {string} str
  @param {object} $parent
  @returns {int}