code: public RecordId getLastDeletedSlot() {
  		Constant blkNum = getVal(OFFSET_LDS_BLOCKID, BIGINT);
  		Constant rid = getVal(OFFSET_LDS_RID, INTEGER);
  		BlockId bid = new BlockId(fileName, (Long) blkNum.asJavaVal());
  		return new RecordId(bid, (Integer) rid.asJavaVal());
  	}
docs: Returns the id of last deleted record.
  
  @return the id of last deleted record