{"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":"//"}]}
            // are `a` and `b`, and while `a` is not directly used in the
            // E.g. in `|b| |c| (a, b, c)`, the upvars of the inner closure
            // outer closure, it needs to be an upvar there too, so that