}
	return filterUnmountedVolumes(mountedVolumes, expectedVolumes)
}

// filterUnmountedVolumes adds each element of expectedVolumes that is not in
// mountedVolumes to a list of unmountedVolumes and returns it.
func filterUnmountedVolumes(mountedVolumes sets.Set[string], expectedVolumes []string) []string {
	unmountedVolumes := []string{}
	for _, expectedVolume := range expectedVolumes {
		if !mountedVolumes.Has(expectedVolume) {

			// Assert
			// Convert to []UniqueVolumeName
			expectedVolumes := make([]v1.UniqueVolumeName, len(tc.expectedVolumesNeedDevicePath))
			for i := range tc.expectedVolumesNeedDevicePath {
				expectedVolumes[i] = v1.UniqueVolumeName(tc.expectedVolumesNeedDevicePath[i])
			}
			if !reflect.DeepEqual(expectedVolumes, rcInstance.volumesNeedUpdateFromNodeStatus) {