{"ast_node_type":"other","tokens":[{"end":70,"kind":"keyword","start":0,"text":"///"}]}
    /// where `'2` is an existential region variable. The type checker
    /// the type of the return slot `_0` is something like `&'2 u32`
    /// requires that `&'2 u32 = &'1 u32` -- but at what point? In the