protected function truncateIdentifier($identifier, $lengthLimit = null, $hashSource = null)
{
if ($lengthLimit === null) {
$lengthLimit = $this->getMaxIdentifierLength();
}
if (strlen($identifier) > $lengthLimit) {
$identifier = substr($identifier, 0, $lengthLimit - 6) . '_' . substr(sha1($hashSource !== null ? $hashSource : $identifier), 0, 5);
}
return $identifier;
}