{"ast_node_type":"other","tokens":[{"end":36,"kind":"keyword","start":0,"text":"///"}]}
            /// E.g., `|x, y| body`.
            Closure(&'a $($mut)? ClosureBinder, &'a $($mut)? Option<CoroutineKind>, &'a $($mut)? P<FnDecl>, &'a $($mut)? P<Expr>),