camera errors

<ipython-input-2-679c11f0396f> in <module>()
      3 if __name__ == '__main__':
      4     settings=CameraController.createCameraSettings(width=640, height=400, exposure=-1)
----> 5     CameraController.openCameras("left_hand_camera", "right_hand_camera", settings=settings)

/home/arpit/catkin_ws/src/lab_baxter_common/baxter_camera_toolkit/python_src/lab_baxter_common/camera_control_helpers.pyc in openCameras(camera, camera2, settings, settings2)
    220                         break
    221         if cameraToClose is not None:
--> 222             CameraController.closeCamera(cameraToClose)
    223 
    224         # Open the specified cameras

/home/arpit/catkin_ws/src/lab_baxter_common/baxter_camera_toolkit/python_src/lab_baxter_common/camera_control_helpers.pyc in closeCamera(camera)
    247             resp = closeService(camera)
    248             if resp.err != 0:
--> 249                 raise OSError("error closing {}: {}".format(camera, resp))
    250         except rospy.ServiceException as err:
    251             raise OSError("error closing %s: %d" % (camera, err))

OSError: error closing head_camera: err: 22