{"ast_node_type":"other","tokens":[{"end":66,"kind":"keyword","start":0,"text":"ty::BoundRegionKind::NamedAnon(_)"}]}
                            ty::BoundRegionKind::NamedAnon(_) => {
                            ty::BoundRegionKind::ClosureEnv => sym::env,
                                bug!("only used for pretty printing")