"""
        if self.cid is not None:
            fetcher = self._create_credentials_fetcher()
            return RefreshableCredentials.create_from_metadata(
                metadata=fetcher(),
                refresh_using=fetcher,
                method=self.METHOD,
            )
        else:
            return None

    def _create_credentials_fetcher(self):
        method = self.METHOD

        def fetch_credentials():

	switch cfg.Name {
	case storageclass.STANDARD, storageclass.RRS:
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, errTierReservedName), r.URL)
		return
	}

	// Refresh from the disk in case we had missed notifications about edits from peers.
	if err := globalTierConfigMgr.Reload(ctx, objAPI); err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}

	if err != nil {
		return nil, err
	}

	// Refresh obtains a fresh token
	err = spt.Refresh()
	if err != nil {
		return nil, err
	}

	tc := azblob.NewTokenCredential(spt.Token().AccessToken, func(tc azblob.TokenCredential) time.Duration {
		err := spt.Refresh()
		if err != nil {
			return 0
		}
		// set the new token value

	// Canceling the context will abort the remote call.
	// In that case, the resource may or may not be unlocked.
	Unlock(ctx context.Context, args LockArgs) (bool, error)

	// Refresh the given lock to prevent it from becoming stale
	Refresh(ctx context.Context, args LockArgs) (bool, error)

	// Unlock (read/write) forcefully for given LockArgs. It should return
	// * a boolean to indicate success/failure of the operation

	lockMap map[string]int64

	// Refresh returns lock not found if set to true
	lockNotFound bool

	// Set to true if you want peers servers to do not respond
	responseDelay int64
}

func (l *lockServer) setRefreshReply(refreshed bool) {
	l.mutex.Lock()
	defer l.mutex.Unlock()
	l.lockNotFound = !refreshed
}

func (l *lockServer) setResponseDelay(responseDelay time.Duration) {

	return restClient.Call("/v1/unlock", args)
}

func (restClient *ReconnectRESTClient) Refresh(ctx context.Context, args LockArgs) (refreshed bool, err error) {
	return restClient.Call("/v1/refresh", args)
}

func (restClient *ReconnectRESTClient) ForceUnlock(ctx context.Context, args LockArgs) (reply bool, err error) {

var errSkipFile = errors.New("skip this file")

var errIgnoreFileContrib = errors.New("ignore this file's contribution toward data-usage")

// errXLBackend XL drive mode requires fresh deployment.
var errXLBackend = errors.New("XL backend requires fresh drive")

// StorageErr represents error generated by xlStorage call.
type StorageErr string

func (h StorageErr) Error() string {
	return string(h)
}

type KeycloakProvider struct {
	sync.Mutex

	oeConfig DiscoveryDoc
	client   http.Client
	adminURL string
	realm    string

	// internal value refreshed
	accessToken Token
}

// LoginWithUser authenticates username/password, not needed for Keycloak
func (k *KeycloakProvider) LoginWithUser(username, password string) error {
	return ErrNotImplemented
}

		return fmt.Errorf("Role %s does not exist", arn)
	}

	jwtToken, err := jp.ParseWithClaims(token, &claims, keyFuncCallback)
	if err != nil {
		// Re-populate the public key in-case the JWKS
		// pubkeys are refreshed
		if err = r.PopulatePublicKey(arn); err != nil {
			return err
		}
		jwtToken, err = jwtgo.ParseWithClaims(token, &claims, keyFuncCallback)
		if err != nil {
			return err
		}
	}

type lockRESTServer struct {
	ll *localLocker
}

// RefreshHandler - refresh the current lock
func (l *lockRESTServer) RefreshHandler(args *dsync.LockArgs) (*dsync.LockResp, *grid.RemoteErr) {
	resp := lockRPCRefresh.NewResponse()
	refreshed, err := l.ll.Refresh(context.Background(), *args)
	if err != nil {
		return l.makeResp(resp, err)
	}
	if !refreshed {
		return l.makeResp(resp, errLockNotFound)
	}
	return l.makeResp(resp, err)