{"ast_node_type":"function","tokens":[{"end":78,"kind":"keyword","start":0,"text":"///"}]}
            /// E.g., `fn foo()`, `fn foo(&self)`, or `extern "Abi" fn foo()`.
        pub enum FnKind<'a> {
            Fn(FnCtxt, &'a $($mut)? Visibility, &'a $($mut)? Fn),