#vulnerable code 
                                private void recordClientSentAnnotations(Endpoint serverAddress) {
        if (serverAddress == null) {
            clientTracer.setClientSent();
        } else {
            clientTracer.setClientSent(serverAddress.ipv4, serverAddress.port, serverAddress.service_name);
        }
    } 
                            #location 5 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                private void recordClientSentAnnotations(Endpoint serverAddress) {
        if (serverAddress == null) {
            clientTracer.setClientSent();
        } else {
            clientTracer.setClientSent(serverAddress);
        }
    }