def METHOD_NAME(f):
    for key in f.GetListOfKeys():
        if key.GetName() == "Events":
            tree = f.Get(key.GetName())
            if isinstance(tree, ROOT.TTree):
                return tree
            elif isinstance(tree, ROOT.TDirectory):
                return METHOD_NAME(tree)
    print('Failed to find TTree Events in file', f)
    return None