@Test

    public void convert64() {

        assertEquals(0xABCDEF0123456780L,

                     DumpArchiveUtil.convert64(new byte[] {

                             (byte) 0x80, 0x67, 0x45, 0x23, 1, (byte) 0xEF,

                             (byte) 0xCD, (byte) 0xAB

                         }, 0));

    }

        long i = 0;

        i += (((long) buffer[offset + 7]) << 56);

        i += (((long) buffer[offset + 6] << 48) & 0x00FF000000000000L);

        i += (((long) buffer[offset + 5] << 40) & 0x0000FF0000000000L);

        i += (((long) buffer[offset + 4] << 32) & 0x000000FF00000000L);

        i += (((long) buffer[offset + 3] << 24) & 0x00000000FF000000L);

        i += (((long) buffer[offset + 2] << 16) & 0x0000000000FF0000L);

        i += (((long) buffer[offset + 1] << 8) & 0x000000000000FF00L);

        i += (((long) buffer[offset]) & 0x00000000000000FFL);

        return i;