public function save()
{
//Save prevalue in column Datatypes\prevalue_value
$arrayResult = array();
$request = $this->getRequest()->getPost();
foreach ($request->get('list', array()) as $idx => $data) {
$key = empty($data['key']) ? $idx : $data['key'];
$arrayResult[$key] = $data['value'];
}
$this->setConfig($arrayResult);
}