protected void doFinish() {
      assert myIndex1 <= myLength1;
      assert myIndex2 <= myLength2;

      if (myLength1 != myIndex1 || myLength2 != myIndex2) {
        addChange(myIndex1, myIndex2, myLength1, myLength2);
        myIndex1 = myLength1;
        myIndex2 = myLength2;
      }
    }
protected void doFinish()