deviceToDetach := operationexecutor.AttachedVolume{VolumeSpec: tmpSpec, PluginName: "fake-file-plugin"}
			err := oex.UnmountDevice(deviceToDetach, asw, hostutil)
			// Assert
			if assert.Error(t, err) {
				assert.Contains(t, err.Error(), tc.expectedErrMsg)
			}
		})
	}
}

			}
			// Clear out the client if specified
			// The lookup to generate a new client will fail
			if tc.unsetClient {
				csiAttacher.csiClient = nil
			}

			// Run
			err := csiAttacher.UnmountDevice(tc.deviceMountPath)
			// Verify
			if err != nil {
				if !tc.shouldFail {
					t.Errorf("test should not fail, but error occurred: %v", err)
				}

	// TimeoutOnMountDeviceVolumeName will cause MountDevice call to timeout but Setup will finish.
	TimeoutOnMountDeviceVolumeName = "timeout-mount-device-volume"
	// TimeoutAndFailOnMountDeviceVolumeName will cause first MountDevice call to timeout but second call will fail
	TimeoutAndFailOnMountDeviceVolumeName = "timeout-and-fail-mount-device-name"
	// FailMountDeviceVolumeName will cause MountDevice operation on volume to fail