public function getKey($key, $exception = true)
    {
        if (!array_key_exists($key, $this->_itemArray)) {
            if ($exception) {
                throw new Exception("Unable to find the requested item key '$key' in item " . var_export($this->_itemArray, true));
            } else {
                return false;
            }
        }
        
        return $this->_itemArray[$key];
    }