{"ast_node_type":"other","tokens":[{"end":90,"kind":"keyword","start":0,"text":"hir::FnRetTy::DefaultReturn(span)"}]}
                            hir::FnRetTy::DefaultReturn(span) => ("()".to_string(), span),
                        let (ty, span) = match fn_decl.output {
                            hir::FnRetTy::Return(ty) => (ty_to_string(&self.tcx, ty), ty.span),