void ExpandAllChildren(const wxTreeItemId& item);
// expand all items
void ExpandAll();
// collapse the item without removing its children
virtual void Collapse(const wxTreeItemId& item) = 0;
void ExpandAllChildren(const wxTreeItemId& item);
// expand all items
void ExpandAll();
// collapse the item without removing its children
virtual void Collapse(const wxTreeItemId& item) = 0;