how to upgrade kinect1's method MapSkeletonPointToDepthPoint

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Kinect

I have a method which is from kinect 1:

private double TrackJointsRotation(KinectSensor sensor, Joint leftJoint, Joint rightJoint)
    {
        if (leftJoint.TrackingState == JointTrackingState.NotTracked
           || rightJoint.TrackingState == JointTrackingState.NotTracked)
            return double.NaN;

        var jointLeftPosition = sensor.CoordinateMapper.MapSkeletonPointToDepthPoint(leftJoint.Position, sensor.DepthStream.Format);
        var jointRightPosition = sensor.CoordinateMapper.MapSkeletonPointToDepthPoint(rightJoint.Position, sensor.DepthStream.Format);

        return -(Math.Atan(((double)jointLeftPosition.Depth - jointRightPosition.Depth)
            / ((double)jointRightPosition.X - jointLeftPosition.X)) * 180.0 / Math.PI);
    }

now i want to upgrade this method to kinect 2. anyone know how to upgrade this?
in kinect 2, the method MapCameraPointToDepthSpace only return DepthSpacePoint object and the object only has X,Y. i want to get the depth value.