anchor.diff:            performanceController.displayRefreshRate.value,
             equals(offlinePerformanceData.displayRefreshRate),
           );
  -
  -        await env.tearDownEnvironment();
         },
         timeout: const Timeout.factor(8),
       );
   
       test('frame selection', () async {
  -      await env.setupEnvironment();
  -
         final frame0 = testFrame0.shallowCopy()
           ..setEventFlow(goldenUiTimelineEvent)
           ..setEventFlow(goldenRasterTimelineEvent);
  
positive.code:         data.timelineEvents,
          matches,
        );
  
        await env.tearDownEnvironment();
      });
    });
  }
  
negative.code:         data.frames.length,
          equals(1),
        );
      });
  
      test('matchesForSearch', () async {
        // Verify an empty list is returned for bad input.
        expect(performanceController.matchesForSearch(''), isEmpty);
  
  