void (@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(); }