Custom gh Component in C#, how to specify type arguments explicitly

My grashopper component should take as an input a data tree.

I have followed the example doing the following for single items:
pManager.AddNumberParameter(“Layer Height”, “LH”, “The layer height of the section.”, GH_ParamAccess.item, 1.0);
and then in Solver instance:
double layerHeight = 0.0;
if (!DA.GetData(1, ref layerHeight)) return;

I want to get a Brep DataTree.
What I did until now is:
pManager.AddBrepParameter(“Object”, “O”, “Object view”, GH_ParamAccess.tree);
and then in Solver instance:
DataTree objectsBrep;
if (!DA.GetDataTree(0, out objectsBrep)) return;

the explanation shows that the input is:
bool DA.GetDataTree() whete t:Brep something like that.

Does anyone have an idea of how to make it work?
If I leave it like that I get the error CS0411


If you are in Visual Studio you need to use GH_Structure<GH_Brep> instead of DataTree.

DA.GetDataTree<GH_Brep>(0, out GH_Structure<GH_Brep> dt);

Then you can access the Brep of any item of this tree using the .Value property.

Are you really sure you need your input as tree ? Those are pretty rare.

In any component/assembly AEC/BIM schema … is the norm (but only if your universe is the GH/R combo).

Thank you!