@Override
    public void readFully(final byte[] b) throws IOException {
        if (read(b) == -1) {
            throw new EOFException("End of stream reached");
        }
    }
@Test
    public void testReadFullyForBOffLen() throws Exception {
        byte[] readFull = new byte[10];
        in.readFully(readFull, 0, 5);
        for (int i = 0; i < 5; i++) {
            assertEquals(readFull[i], in.data[i]);
        }
    }