func (client *storageRESTClient) DeleteVol(ctx context.Context, volume string, forceDelete bool) (err error) {
	return errInvalidArgument
}

// AppendFile - append to a file.
func (client *storageRESTClient) AppendFile(ctx context.Context, volume string, path string, buf []byte) error {
	values := make(url.Values)
	values.Set(storageRESTVolume, volume)
	values.Set(storageRESTFilePath, path)