public function getAllKeys()
{
// initialize the array with keys of all attributes
$keys = array();
// prepare the pattern to filter the attributes
$pattern = sprintf('%s-*', $this->getSerial());
// prepare the array with the attribute keys
foreach (array_keys((array) $this) as $key) {
if (fnmatch($pattern, $key)) {
$keys[] = $this->unmaskKey($key);
}
}
// return the attribute keys
return $keys;
}