[Microstation Connect] How to create a GroupedHole Element with a AreaPattern

Good morning,
I have a problem with creating PatternArea on an object of type GroupedHoleElement,
I would like to create a groupedHole like this:

the Microstation version is the following: Microstation CONNECT Edition Update 12 - Version 10.12.00.40.
Given that I have already searched for a solution or examples in the SDK example .. \ Elements \ ManagedToolsExample and I have not found anything about it, I report below the code I wrote in C #.

GroupedHoleElement groupedHoleElement = currElement as GroupedHoleElement;
PatternParams patternParams = new PatternParams ();
patternParams.CellName = "A0A"; <- This field must contain the name of a model from the tmplate.cel library linked to the working file
patternParams.PrimarySpacing = 1
patternParams.SecondarySpacing = 1
patternParams.PrimaryAngle = 45
patternParams.Scale = 1;

DwgHatchDefLine dwgHatchDefLine = new DwgHatchDefLine ();
dwgHatchDefLine.Angle = 45;

DwgHatchDefLine [] dwgHatchDefLines = new DwgHatchDefLine [1];
dwgHatchDefLines [0] = dwgHatchDefLine;

groupedHoleElement.AddPattern (patternParams, dwgHatchDefLines, 0);

The code is executed without errors, only that in the output the selected element has no pattern,
would you have a working example in c #?


Thanks so much,

best regards

Salvio