code: private void moveToNextBlock() {
  		blk = new BlockId(blk.fileName(), blk.number() - 1);
  		pg.read(blk);
  		currentRec = (Integer) pg.getVal(LogMgr.LAST_POS, INTEGER).asJavaVal();
  	}
docs: Moves to the next log block in reverse order, and positions it after the
  last record in that block.