private static void verifyFullCover(@NotNull DiffIterable iterable) {
    int last1 = 0;
    int last2 = 0;
    Boolean lastEquals = null;

    for (Pair<Range, Boolean> pair : iterateAll(iterable)) {
      Range range = pair.first;
      Boolean equal = pair.second;

      assert last1 == range.start1;
      assert last2 == range.start2;
      assert !Comparing.equal(lastEquals, equal);

      last1 = range.end1;
      last2 = range.end2;
      lastEquals = equal;
    }

    assert last1 == iterable.getLength1();
    assert last2 == iterable.getLength2();
  }
private static void verifyFullCover(@NotNull DiffIterable iterable)