code: @Override
    public void writeLong(long v) throws IOException {
      byte[] bytes = Longs.toByteArray(Long.reverseBytes(v));
      write(bytes, 0, bytes.length);
    }
docs: Writes a {@code long} as specified by {@link DataOutputStream#writeLong(long)}, except using
  little-endian byte order.
  
  @throws IOException if an I/O error occurs