{"ast_node_type":"other","tokens":[{"end":87,"kind":"keyword","start":0,"text":"ty::BoundVariableKind::Region(ty::BoundRegionKind::ClosureEnv),"}]}
                        ty::BoundVariableKind::Region(ty::BoundRegionKind::ClosureEnv),
                    inputs_and_output.bound_vars().iter().chain(iter::once(
                    )),