NSDictionary *userInfo = CFBridgingRelease(contextInfo);
NJMapping *oldMapping = userInfo[@"old mapping"];
NJMapping *newMapping = userInfo[@"new mapping"];
NSDictionary *userInfo = CFBridgingRelease(contextInfo);
NJMapping *oldMapping = userInfo[@"old mapping"];
NJMapping *newMapping = userInfo[@"new mapping"];