{"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"Self::LateBoundary"}]}
            Self::LateBoundary { s: _, what, deny_late_regions } => f
            Self::TraitRefBoundary { s: _ } => f.debug_struct("TraitRefBoundary").finish(),
                .debug_struct("LateBoundary")