ListDir(ctx context.Context, origvolume, volume, dirPath string, count int) ([]string, error)
	ReadFile(ctx context.Context, volume string, path string, offset int64, buf []byte, verifier *BitrotVerifier) (n int64, err error)
	AppendFile(ctx context.Context, volume string, path string, buf []byte) (err error)
	CreateFile(ctx context.Context, origvolume, olume, path string, size int64, reader io.Reader) error

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)

	"context"
	"crypto/rand"
	"io"
	"testing"

	"github.com/dustin/go-humanize"
)

type badDisk struct{ StorageAPI }

func (a badDisk) String() string {
	return "bad-disk"
}

func (a badDisk) AppendFile(ctx context.Context, volume string, path string, buf []byte) error {
	return errFaultyDisk
}

func (a badDisk) ReadFileStream(ctx context.Context, volume, path string, offset, length int64) (io.ReadCloser, error) {

func (p *xlStorageDiskIDCheck) AppendFile(ctx context.Context, volume string, path string, buf []byte) (err error) {
	ctx, done, err := p.TrackDiskHealth(ctx, storageMetricAppendFile, volume, path)
	if err != nil {
		return err
	}
	defer done(&err)

	w := xioutil.NewDeadlineWorker(globalDriveConfig.GetMaxTimeout())
	return w.Run(func() error {
		return p.storage.AppendFile(ctx, volume, path, buf)
	})
}

	if err != nil {
		return err
	}

	return s.writeAll(ctx, volume, path, b, true, volumeDir)
}

// AppendFile - append a byte array at path, if file doesn't exist at
// path this call explicitly creates it.
func (s *xlStorage) AppendFile(ctx context.Context, volume string, path string, buf []byte) (err error) {
	volumeDir, err := s.getVolDir(volume)
	if err != nil {
		return err
	}

	filePath := r.Form.Get(storageRESTFilePath)

	buf := make([]byte, r.ContentLength)
	_, err := io.ReadFull(r.Body, buf)
	if err != nil {
		s.writeErrorResponse(w, err)
		return
	}
	err = s.getStorage().AppendFile(r.Context(), volume, filePath, buf)
	if err != nil {
		s.writeErrorResponse(w, err)
	}
}

// CreateFileHandler - copy the contents from the request.