#vulnerable code 
                                public ByteBuffer[] toUDPBuffers() {

        byte[] messageBytes = gzipMessage(toJsonByteArray("_"));

        if (messageBytes.length > maximumMessageSize) {
            // calculate the length of the datagrams array
            int datagrams_length = messageBytes.length / maximumMessageSize;
            // In case of a remainder, due to the integer division, add a extra datagram
            if (messageBytes.length % maximumMessageSize != 0) {
                datagrams_length++;
            }

            ByteBuffer targetBuffer = ByteBuffer.allocate(messageBytes.length + (datagrams_length * 12));

            return sliceDatagrams(ByteBuffer.wrap(messageBytes), datagrams_length, targetBuffer);
        }

        ByteBuffer[] datagrams = new ByteBuffer[1];
        datagrams[0] = ByteBuffer.allocate(messageBytes.length);
        datagrams[0].put(messageBytes);
        datagrams[0].flip();
        return datagrams;
    } 
                            #location 5 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public ByteBuffer[] toUDPBuffers() {

        byte[] messageBytes = gzipMessage(toJsonByteArray("_"));

        if (messageBytes.length > maximumMessageSize) {
            // calculate the length of the datagrams array
            int datagramsLength = messageBytes.length / maximumMessageSize;
            // In case of a remainder, due to the integer division, add a extra datagram
            if (messageBytes.length % maximumMessageSize != 0) {
                datagramsLength++;
            }

            ByteBuffer targetBuffer = ByteBuffer.allocate(messageBytes.length + (datagramsLength * 12));

            return sliceDatagrams(ByteBuffer.wrap(messageBytes), datagramsLength, targetBuffer);
        }

        ByteBuffer[] datagrams = new ByteBuffer[1];
        datagrams[0] = ByteBuffer.allocate(messageBytes.length);
        datagrams[0].put(messageBytes);
        datagrams[0].flip();
        return datagrams;
    }