code: function deepClone(item) {
    let clone = item;
    if (isArray(item)) {
      clone = new Array(item.length);
      item.forEach((child, key) => {
        clone[key] = deepClone(child);
      });
    } else if (item && typeOf(item) === 'object') {
      clone = {};
      keys(item).forEach(key => {
        clone[key] = deepClone(item[key]);
      });
    }
    return clone;
  }
docs: Recursively clones all arrays. Needed because Chrome
  refuses to clone Ember Arrays when extend prototypes is disabled.
  
  If the item passed is an array, a clone of the array is returned.
  If the item is an object or an array, or array properties/items are cloned.
  
  @param {Mixed} item The item to clone
  @return {Mixed}