{"ast_node_type":"other","tokens":[{"end":94,"kind":"keyword","start":0,"text":"//"}]}
                            // Foo { field: ref mut local } -> Foo { field: ref mut new_name }
                            // Foo { field: ref mut local @ local 2} -> Foo { field: ref mut new_name @ local2 }
                            //                      ^^^^^ replace this with `new_name`