anchor.diff:              if (shift == 0) {
                 expect(target, source);
               } else if (shift >= len) {
  -              expect(target.any((x) => x), isFalse);
  +              expect(target, everyElement(isFalse));
               } else {
                 for (var i = 0; i < source.length - shift; i++) {
                   expect(target[i], source[i + shift]);
  
positive.code:           var target = new BitList(len);
            expect(target, isNot(isEmpty));
            expect(target, hasLength(len));
            expect(target.every((value) => value == false), isTrue);
          }
        });
        test('from List', () {
  
negative.code:             if (shift == 0) {
                expect(target, source);
              } else if (shift >= len) {
                expect(target, everyElement(isFalse));
              } else {
                for (var i = shift; i < source.length; i++) {
                  expect(target[i], source[i - shift]);
  