code: public function offsetGet($Offset)
      {
          if(array_key_exists($Offset, $this->_data))
                  return $this->_data[$Offset];
          return null;
      }
docs: Offset to retrieve
  @link http://php.net/manual/en/arrayaccess.offsetget.php
  @param mixed $Offset The offset to retrieve.
  @return mixed Can return all value types.