#include <TGeoManager.h>
#include <TEveManager.h>

void save_extract(TString file)
{
   TEveManager::Create();
   gGeoManager = gEve->GetGeometry(file);
   auto node   = gGeoManager->GetTopNode();
   if (!node) return ;
   auto evenode = new TEveGeoTopNode(gGeoManager, node);
   evenode->ExpandIntoListTrees();
   gEve->AddGlobalElement(evenode);
   gEve->Redraw3D(kTRUE);
   evenode->SaveExtract("test_extract.root", "Extract", false);

}