private void addUnchanged(int start1, int start2, int count) {
    myChanges1.set(myStart1 + start1, myStart1 + start1 + count, false);
    myChanges2.set(myStart2 + start2, myStart2 + start2 + count, false);
  }
private void addUnchanged(int start1, int start2, int count)