Checklist

• I have searched for similar issues.
• For Python issues, I have tested with the latest development wheel.
• I have checked the release documentation and the latest documentation (for main branch).

Proposed new feature or change

When adding many items to the TreeView (with different hierarchies) the widget get crowded very quickly. It's possible to collapse and open a single parent item from the interface with the mouse, but I could not find a way to do it from code.

I would like to have the option to collapse and open them via code.

References

No response

Additional information

No response