// Verify response to field if present, set request if correct
// The inResponseTo field is optional, SAML 2.0 Core, 1542
SAMLMessageStorage messageStorage = context.getMessageStorage();
if (messageStorage != null && response.getInResponseTo() != null) {
XMLObject xmlObject = messageStorage.retrieveMessage(response.getInResponseTo());
if (xmlObject == null) {
throw new SAMLException("InResponseToField in LogoutResponse doesn't correspond to sent message " + response.getInResponseTo());
} else if (xmlObject instanceof LogoutRequest) {
// Expected
} else {