#vulnerable code 
                                @Test
    public void testSimpledSingleThreadedWriteRead() throws Exception {

        try (DirectStore  allocate = DirectStore.allocate(150)) {

            final BytesQueue bytesRingBuffer = new BytesQueue(allocate.bytes());

            bytesRingBuffer.offer(output.clear());
            Bytes poll = bytesRingBuffer.poll(input.clear());
            assertEquals(EXPECTED, poll.readUTF());
        }
    } 
                            #location 10 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    public void testSimpledSingleThreadedWriteRead() throws Exception {

        try (DirectStore allocate = DirectStore.allocate(150)) {

            final BytesRingBuffer bytesRingBuffer = new BytesRingBuffer(allocate.bytes());

            bytesRingBuffer.offer(output.clear());
            Bytes actual = bytesRingBuffer.take(maxSize -> input.clear());
            assertEquals(EXPECTED, actual.readUTF());
        }
    }