func exponentialBackoffWait(r *rand.Rand, unit, cap time.Duration) func(uint) time.Duration {
	if unit > time.Hour {
		// Protect against integer overflow
		panic("unit cannot exceed one hour")
	}
	return func(attempt uint) time.Duration {
		if attempt > 16 {
			// Protect against integer overflow
			attempt = 16
		}
		// sleep = random_between(unit, min(cap, base * 2 ** attempt))

			return nil
		case objectlock.RetGovernance:
			// In governance mode, users can't overwrite or delete an object
			// version or alter its lock settings unless they have special
			// permissions. With governance mode, you protect objects against
			// being deleted by most users, but you can still grant some users
			// permission to alter the retention settings or delete the object

	xioutil "github.com/minio/minio/internal/ioutil"
	"github.com/minio/minio/internal/kms"
	"github.com/puzpuzpuz/xsync/v3"
)

// IAMObjectStore implements IAMStorageAPI
type IAMObjectStore struct {
	// Protect access to storage within the current server.
	sync.RWMutex

	*iamCache

	cachedIAMListing atomic.Value

	usersSysType UsersSysType

	objAPI ObjectLayer
}