{"ast_node_type":"function","tokens":[{"end":78,"kind":"keyword","start":0,"text":"fn"}]}
        fn visit_poly_trait_ref(&mut self, trait_ref: &'a ast::PolyTraitRef) {
        // Place bound generic params on a stack, to extract them when a type is encountered.
            let stack_len = self.bound_generic_params_stack.len();