internal static CoordinateSystem AtParameterCore(Surface contextSurface, double u, double v, bool visible)
{
if (contextSurface == null)
throw new System.ArgumentNullException("contextSurface");
var cs = contextSurface.GetCSAtParameters(u, v);
if (null == cs)
throw new System.Exception(string.Format(Properties.Resources.OperationFailed, "CoordinateSystem.AtParameter"));
cs.ContextSurface = contextSurface;
cs.U = u;
cs.V = v;
cs.Visible = visible;
return cs;
}