{"ast_node_type":"other","tokens":[{"end":44,"kind":"keyword","start":0,"text":")"}]}
    ) -> InterpResult<'tcx, (Size, Align)> {
        expected_trait: Option<&'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>>,
        let ty = self.get_ptr_vtable_ty(vtable, expected_trait)?;