public void cutSameTail() {
      final BeforeAfter<List<String>> lastStep = myPatchSteps.get(myPatchSteps.size() - 1);
      final List<String> before = lastStep.getBefore();
      final List<String> after = lastStep.getAfter();
      int cntBefore = before.size() - 1;
      int cntAfter = after.size() - 1;

      for (; cntBefore >= 0 && cntAfter > 0; cntBefore--, cntAfter--) {
        if (! before.get(cntBefore).equals(after.get(cntAfter))) break;
      }

      // typically only 1 line
      int cutSame = before.size() - 1 - cntBefore;
      for (int i = 0; i < cutSame; i++) {
        before.remove(before.size() - 1);
        after.remove(after.size() - 1);
      }
    }
public void cutSameTail()