code: function _getKeys(json, aKeys) {
      var aKey,
        sKey,
        oItem;
  
      for (sKey in json) {
  
        if (json.hasOwnProperty(sKey)) {
          oItem = json[sKey];
          if (_isObject(oItem) || _isArray(oItem)) {
            aKeys = aKeys.concat(unique(_getKeys(oItem, aKeys)));
          }
          if (isNaN(Number(sKey))) {
            if (!contains(aKeys, sKey)) {
              _nCode += 1;
              aKey = [];
              aKey.push(_getSpecialKey(_numberToKey(_nCode)), sKey);
              aKeys.push(aKey);
            }
          }
        }
      }
      return aKeys;
    }
docs: Traverse all the objects looking for keys and set an array with the new keys
  @param json
  @param aKeys
  @returns {*}
  @private