{"ast_node_type":"variable","tokens":[{"end":59,"kind":"keyword","start":0,"text":"let"}]}
        let (alloc, machine) = self.get_alloc_raw_mut(id)?;
    ) -> InterpResult<'tcx, (&'a mut M::AllocExtra, &'a mut M)> {
        interp_ok((&mut alloc.extra, machine))