type StorageAPI interface {
	// Stringified version of disk.
	String() string

	// Storage operations.

	// Returns true if disk is online and its valid i.e valid format.json.
	// This has nothing to do with if the drive is hung or not responding.
	// For that individual storage API calls will fail properly. The purpose
	// of this function is to know if the "drive" has "format.json" or not

	lastSuccess int64

	// atomic time of last time a token was grabbed.
	lastStarted int64

	// Atomic status of disk.
	status atomic.Int32

	// Atomic number indicates if a disk is hung
	waiting atomic.Int32
}

// newDiskHealthTracker creates a new disk health tracker.
func newDiskHealthTracker() *diskHealthTracker {
	d := diskHealthTracker{
		lastSuccess: time.Now().UnixNano(),