public String prettyHexDump() {
        final ByteBuf buffer = Unpooled.buffer(20);
        try {
            buffer.writeShort(version());
            buffer.writeShort(count());
            buffer.writeInt(Math.toIntExact(sysUptime()));
            buffer.writeInt(Math.toIntExact(unixSecs()));
            buffer.writeInt(Math.toIntExact(sequence()));
            buffer.writeInt(Math.toIntExact(sourceId()));

            return ByteBufUtil.prettyHexDump(buffer);
        } finally {
            ReferenceCountUtil.release(buffer);
        }
    }
@Test
    public void prettyHexDump() {
        final NetFlowV9Header header = NetFlowV9Header.create(5, 23, 42L, 1000L, 1L, 1L);
        assertThat(header.prettyHexDump()).isNotEmpty();
    }