{"ast_node_type":"import","tokens":[{"end":76,"kind":"keyword","start":0,"text":"///"}]}
    /// which has no `external_name` in which case we use `'{erased}` as the
    /// Calling `universal_upper_bound` for such a region gives `fr_fn_body`,
    /// region to pass to `infer_opaque_definition_from_instantiation`.