How does stalePeriod work?

[emiraksamyatmazsabahkalkmaz]

I passed a cacheManager to the CachedNetworkImage widget we are using.

To test whether the image is deleted from the cache or not, I set the stalePeriod to 5 seconds. Like this:

CachedNetworkImage(
      imageUrl: "myimagelink"
      cacheManager: CustomCacheManager.instance,
),

// ...

class CustomCacheManager {
  static const key = DefaultCacheManager.key;
  static CacheManager instance = CacheManager(
    Config(
      key,
      stalePeriod: const Duration(seconds: 5),
    ),
  );
}

However, the cache manager is not working as expected. If an image is cached and then not used for 5 seconds, shouldn't it be automatically deleted from the cache? We believe it should work this way. Or do we need to delete it manually?