protected function filterPrivileges(array $privileges)
{
foreach ($privileges as $httpMethod => $flag) {
if (!array_key_exists($httpMethod, $this->defaultPrivileges)) {
unset($privileges[$httpMethod]);
continue;
}
if (!is_bool($flag)) {
$privileges[$httpMethod] = (bool) $flag;
continue;
}
}
return $privileges;
}