{"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"ast::GenericArg::AssocTypeArg(a)"}]}
                                ast::GenericArg::AssocTypeArg(a)
                            match p.generic_arg_list()?.generic_args().next()? {
                                    if a.name_ref()?.text() == "Output" =>