protected void addChange(int start1, int start2, int start3, int end1, int end2, int end3) {
      if (start1 == end1 && start2 == end2 && start3 == end3) return;
      myChanges.add(new MergeRange(start1, end1, start2, end2, start3, end3));
    }
protected void addChange(int start1, int start2, int start3, int end1, int end2, int end3)