How to create a revolution surface from b-spline

I have a b-spline and I need to create a surface of revolution from it without using sketches (by using IBody2.CreateRevolutionSurface). Here is a C# sample code:

var part = SwApp.IActiveDoc2 as IPartDoc;

var selMgr = SwApp.IActiveDoc2.SelectionManager as ISelectionMgr;

var selCurve = selMgr.GetSelectedObject6(1, -1) as ISketchSegment;

if (selCurve != null)

{

    var swCurveIn = (ICurve)selCurve.GetCurve();

    var body = part.ICreateNewBody2();

    double[] point = new double[] { 0, 0, 0 };

    double[] axis = new double[] { 0, 0, 1 };

    double[] coords = new double[] { 0, Math.PI };

    var surface = body.CreateRevolutionSurface(swCurveIn, point, axis, coords) as ISurface;

}

I create a b-spline sketch, select it and run this code.

Here is an example of spline I create. Line is just a center line.

CreateRevolutionSurface always returns null no matter what point and axis I take. But it works fine if I use for example line, arc or ellipse.

Is it possible to create a revolve from spline using CreateRevolutionSurface? If yes, please share a code sample in any language.

Thanks

SolidworksApi macros