public void markEqual(int start1, int start2, int start3, int end1, int end2, int end3) {
      assert myIndex1 <= start1;
      assert myIndex2 <= start2;
      assert myIndex3 <= start3;
      assert start1 <= end1;
      assert start2 <= end2;
      assert start3 <= end3;

      processChange(myIndex1, myIndex2, myIndex3, start1, start2, start3);

      myIndex1 = end1;
      myIndex2 = end2;
      myIndex3 = end3;
    }
public void markEqual(int start1, int start2, int start3, int end1, int end2, int end3)