// Attach is part of the volume.Attacher interface
func (a *flexVolumeAttacher) Attach(spec *volume.Spec, hostName types.NodeName) (string, error) {

	call := a.plugin.NewDriverCall(attachCmd)
	call.AppendSpec(spec, a.plugin.host, nil)
	call.Append(string(hostName))

	status, err := call.Run()
	if isCmdNotSupportedErr(err) {
		return (*attacherDefaults)(a).Attach(spec, hostName)
	} else if err != nil {
		return "", err

)

func (plugin *flexVolumePlugin) ExpandVolumeDevice(spec *volume.Spec, newSize resource.Quantity, oldSize resource.Quantity) (resource.Quantity, error) {
	call := plugin.NewDriverCall(expandVolumeCmd)
	call.AppendSpec(spec, plugin.host, nil)

	devicePath, err := plugin.getDeviceMountPath(spec)
	if err != nil {
		return newSize, err
	}
	call.Append(devicePath)
	call.Append(strconv.FormatInt(newSize.Value(), 10))

	}
}

// Append appends arg into driver call argument list
func (dc *DriverCall) Append(arg string) {
	dc.args = append(dc.args, arg)
}

// AppendSpec appends volume spec to driver call argument list
func (dc *DriverCall) AppendSpec(spec *volume.Spec, host volume.VolumeHost, extraOptions map[string]string) error {
	optionsForDriver, err := NewOptionsForDriver(spec, host, extraOptions)
	if err != nil {
		return err

		os.Remove(dir)
		return err
	}

	// Implicit parameters
	if mounterArgs.FsGroup != nil {
		extraOptions[optionFSGroup] = strconv.FormatInt(int64(*mounterArgs.FsGroup), 10)
	}

	call.AppendSpec(f.spec, f.plugin.host, extraOptions)

	_, err = call.Run()
	if isCmdNotSupportedErr(err) {
		err = (*mounterDefaults)(f).SetUpAt(dir, mounterArgs)
	}

	if err != nil {
		os.Remove(dir)
		return err
	}

}

// GetVolumeName is part of the volume.VolumePlugin interface.
func (plugin *flexVolumePlugin) GetVolumeName(spec *volume.Spec) (string, error) {
	call := plugin.NewDriverCall(getVolumeNameCmd)
	call.AppendSpec(spec, plugin.host, nil)

	_, err := call.Run()
	if isCmdNotSupportedErr(err) {
		return (*pluginDefaults)(plugin).GetVolumeName(spec)
	} else if err != nil {
		return "", err
	}