volumeToUnmount := operationexecutor.MountedVolume{
				PluginName: "fake-file-plugin",
				VolumeSpec: tmpSpec}
			err := oex.UnmountVolume(volumeToUnmount, asw, "" /* podsDir */)
			// Assert
			if assert.Error(t, err) {
				assert.Contains(t, err.Error(), tc.expectedErrMsg)
			}
		})
	}
}