code: function compareAscending(a, b) {
      var ac = a.criteria,
          bc = b.criteria,
          index = -1,
          length = ac.length;
  
      while (++index < length) {
        var value = ac[index],
            other = bc[index];
  
        if (value !== other) {
          if (value > other || typeof value == 'undefined') {
            return 1;
          }
          if (value < other || typeof other == 'undefined') {
            return -1;
          }
        }
      }
      // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications
      // that causes it, under certain circumstances, to return the same value for
      // `a` and `b`. See https://github.com/jashkenas/underscore/pull/1247
      //
      // This also ensures a stable sort in V8 and other engines.
      // See http://code.google.com/p/v8/issues/detail?id=90
      return a.index - b.index;
    }
docs: Used by `sortBy` to compare transformed `collection` elements, stable sorting
  them in ascending order.
  
  @private
  @param {Object} a The object to compare to `b`.
  @param {Object} b The object to compare to `a`.
  @returns {number} Returns the sort order indicator of `1` or `-1`.