public void ValidatePolygonRing()
{
GeometryPipeline v = new SpatialValidatorImplementation();
v.SetCoordinateSystem(NonDefaultGeometricCoords);
v.BeginGeometry(SpatialType.Polygon);
v.BeginFigure(new GeometryPosition(10, 20, 30, 40));
v.LineTo(new GeometryPosition(20, 30, 40, 50));
v.LineTo(new GeometryPosition(20, 40, 40, 50));
v.LineTo(new GeometryPosition(10, 20, 30, 40));
v.EndFigure();
v.EndGeometry();
}