public Slot debugReadPointerSlot(int id) {
   if (Deploy.debug) {
     readBytes(_pointerIo._buffer, id, Const4.POINTER_LENGTH);
     _pointerIo.seek(0);
     _pointerIo.readBegin(Const4.YAPPOINTER);
     int debugAddress = _pointerIo.readInt();
     int debugLength = _pointerIo.readInt();
     _pointerIo.readEnd();
     return new Slot(debugAddress, debugLength);
   }
   return null;
 }
 public void writePointer(int id, Slot slot) {
   if (DTrace.enabled) {
     DTrace.WRITE_POINTER.log(id);
     DTrace.WRITE_POINTER.logLength(slot);
   }
   _pointerIo.seek(0);
   if (Deploy.debug) {
     _pointerIo.writeBegin(Const4.YAPPOINTER);
   }
   _pointerIo.writeInt(slot.address());
   _pointerIo.writeInt(slot.length());
   if (Deploy.debug) {
     _pointerIo.writeEnd();
   }
   if (Debug4.xbytes) {
     _pointerIo.checkXBytes(false);
   }
   writeBytes(_pointerIo, id, 0);
 }