{"ast_node_type":"function","tokens":[{"end":84,"kind":"keyword","start":0,"text":"fn"}]}
    fn flat_map_item(&mut self, node: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> {
        self.flat_map_node(node)