// The returned value can no longer be modified once returned.
	// Should be set before calling Get().
	updateFn func() (T, error)

	// ttl for a cached value.
	ttl time.Duration

	opts Opts

	// Once can be used to initialize values for lazy initialization.
	// Should be set before calling Get().
	Once sync.Once

	// Managed values.
	valErr atomic.Pointer[struct {
		v T
		e error
	}]

		Value: "",
	},
}

// Config represents the subnet related configuration
type Config struct {
	// Flag indicating whether cache is enabled.
	Enable bool `json:"enable"`

	// Endpoint for caching uses remote mcache server to
	// store and retrieve pre-condition check entities such as
	// Etag and ModTime of an object + version
	Endpoint string `json:"endpoint"`