{"ast_node_type":"function","tokens":[{"end":93,"kind":"keyword","start":0,"text":"fn"}]}
    fn increase_complexity_level(&mut self, complexity_add: usize) -> Result<(), Cx::Error> {
impl<'a, 'p, Cx: PatCx> UsefulnessCtxt<'a, 'p, Cx> {
        self.complexity_level += complexity_add;