public function setProtectionPolicy($protectionPolicy)
{
if ($protectionPolicy !== GuardInterface::POLICY_ALLOW && $protectionPolicy !== GuardInterface::POLICY_DENY) {
throw new Exception\RuntimeException(sprintf('An invalid protection policy was set. Can only be "deny" or "allow", "%s" given', $protectionPolicy));
}
$this->protectionPolicy = (string) $protectionPolicy;
}