code: function arrays(arr, i) {
    var values = filterType(arr, 'array');
    return i ? values[i] : values;
  }
docs: Filter `array`, returning only the arrays.
  
  ```js
  var arr = ['a', ['aaa'], 1, 'b', ['bbb'], 2, {c: 'd'}, 'c'];
  
  utils.objects(arr);
  //=> [['aaa'], ['bbb']]
  ```
  
  @param  {Array} `array`
  @param  {Array} `index` Optionally specify the index of the array to return, otherwise all arrays are returned.
  @return {Array} Array of arrays or empty array.
  @api public