{"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"self.v.get_mut(Self::to_idx(idx)).and_then(|it|"}]}
        self.v.get_mut(Self::to_idx(idx)).and_then(|it| it.as_mut())
    pub fn get_mut(&mut self, idx: Idx<T>) -> Option<&mut V> {
    }