{"ast_node_type":"function","tokens":[{"end":79,"kind":"keyword","start":0,"text":"//"}]}
            //   fn flat_map_t(&mut self, t: T) -> SmallVec<[T; 1]>;    // rare
            //   fn visit_t(&mut self, t: &mut T);                      // common
            //   fn filter_map_t(&mut self, t: T) -> Option<T>;         // rarest