anchor.diff:        flameTester.test(
           'lower translation limit as negative infinity',
           (game) async {
  +          await game.ensureAddAll([plunger, anchor]);
  +
             final jointDef = PlungerAnchorPrismaticJointDef(
               plunger: plunger,
               anchor: anchor,
  
positive.code:   });
  
    group('PlungerAnchorPrismaticJointDef', () {
      final plunger = Plunger(Vector2.zero())..createBody();
      final anchor = Plunger(Vector2(0, -5))..createBody();
  
      group('initializes with', () {
        flameTester.test(
          'plunger as bodyA',
          (game) async {
            final jointDef = PlungerAnchorPrismaticJointDef(
              plunger: plunger,
              anchor: anchor,
  
negative.code:       flameTester.test(
          'limits enabled',
          (game) async {
            await game.ensureAddAll([plunger, anchor]);
  
            final jointDef = PlungerAnchorPrismaticJointDef(
              plunger: plunger,
              anchor: anchor,
  