protected function getIdentifierNormalizationFilter()
{
if (isset($this->filters['identifier']) && $this->filters['identifier'] instanceof FilterChain) {
return $this->filters['identifier'];
}
$filter = new FilterChain();
$filter->attachByName('WordCamelCaseToUnderscore')->attachByName('StringToLower');
$this->filters['identifier'] = $filter;
return $filter;
}