code: @Test public void shouldAssumeResourceNotChangedWhenStreamIsUnavailable() throws Exception {
    victim=new ResourceWatcher(){
      @Override void onGroupChanged(    final CacheKey cacheEntry){
        super.onGroupChanged(cacheEntry);
        Assert.fail("Should not detect the change");
      }
    }
  ;
    createDefaultInjector().inject(victim);
    final ResourceChangeDetector mockChangeDetector=Mockito.spy(victim.getResourceChangeDetector());
    Mockito.when(mockLocator.locate(Mockito.anyString())).thenThrow(new IOException("Resource is unavailable"));
    victim.check(cacheEntry);
    verify(mockChangeDetector,never()).checkChangeForGroup(Mockito.anyString(),Mockito.anyString());
  }
  