code: function shuffle(array) {
      if (!array) {
        return [];
      }
      var rand,
          index = -1,
          length = array.length,
          result = Array(length);
  
      while (++index < length) {
        rand = Math.floor(Math.random() * (index + 1));
        result[index] = result[rand];
        result[rand] = array[index];
      }
      return result;
    }
docs: Produces a new array of shuffled `array` values, using a version of the
  Fisher-Yates shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle.
  
  @static
  @memberOf _
  @category Arrays
  @param {Array} array The array to shuffle.
  @returns {Array} Returns a new shuffled array.
  @example
  
  _.shuffle([1, 2, 3, 4, 5, 6]);
  // => [4, 1, 6, 3, 5, 2]