{"ast_node_type":"function","tokens":[{"end":91,"kind":"keyword","start":0,"text":"pub"}]}
    pub fn map<U: ?Sized>(this: Self, f: impl FnOnce(&T) -> &U) -> FreezeReadGuard<'a, U> {
    #[inline]
        FreezeReadGuard { data: NonNull::from(f(&*this)), _lock_guard: this._lock_guard }