{"ast_node_type":"other","tokens":[{"end":97,"kind":"keyword","start":0,"text":"//"}]}
        // `longer_fr` and `shorter_fr` terminology will still be used here, for consistency with
        // Polonius doesn't model regions ("origins") as CFG-subsets or durations, but the
        // the rest of the NLL infrastructure. The "subset origin" is the "longer free region",