syntax_data: {"ast_node_type":"other","tokens":[{"end":61,"kind":"keyword","start":0,"text":"ty::Tuple(ts)"}]}
source_snippet:             ty::Tuple(ts) => ty::Tuple(ts.fold_with(folder)),
context_before:             }
context_after:             ty::FnDef(def_id, args) => ty::FnDef(def_id, args.fold_with(folder)),