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:     });
      group('accessors', () {
        test('reading', () {
          for (var i = 0; i < 100; i++) {
            var list = new BitList(i);
            expect(() => list[-1], throwsRangeError);
            for (var j = 0; j < i; j++) {
              expect(() => list[j], returnsNormally);
            }
            expect(() => list[i], throwsRangeError);
          }
        });
        test('writing', () {
          for (var i = 0; i < 100; i++) {
            var list = new BitList(i);
            expect(() => list[-1] = true, throwsRangeError);
            for (var j = 0; j < i; j++) {
              expect(() => list[j] = true, returnsNormally);
              expect(list[j], isTrue);
            }
            expect(() => list[i] = true, throwsRangeError);
          }
        });
        test('flipping', () {
  
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]);
  