protected function _normalizeArray($value)
    {
        if ($value instanceof stdClass) {
            $value = (array) $value;
        }

        if (is_array($value)) {
            return $value;
        }

        if (!($value instanceof Traversable)) {
            throw $this->_createInvalidArgumentException($this->__('Not an iterable'), null, null, $value);
        }

        $value = iterator_to_array($value, true);

        return $value;
    }