code: private void writeULong(int s) {
          byte b1 = (byte)((s >> 24) & 0xff);
          byte b2 = (byte)((s >> 16) & 0xff);
          byte b3 = (byte)((s >> 8) & 0xff);
          byte b4 = (byte)(s & 0xff);
          writeByte(b1);
          writeByte(b2);
          writeByte(b3);
          writeByte(b4);
      }
docs: Appends a ULONG to the output array,
  updates currentPos but not realSize
  
  @param s The value to write