{"ast_node_type":"other","tokens":[{"end":87,"kind":"keyword","start":0,"text":"///"}]}
    /// does not contain lifetimes, which are instead in the `FreeRegionMap`, and other
    /// FIXME: Your first reaction may be that this is a bit strange. `RegionBoundPairs`
    /// known type outlives are stored in the `known_type_outlives` set. So why do we