{"ast_node_type":"variable","tokens":[{"end":76,"kind":"keyword","start":0,"text":"let"}]}
            let cause = ObligationCause::misc(expr.span, self.mir_def_id());
            let ocx = ObligationCtxt::new_with_diagnostics(self.infcx);
            ocx.register_bound(cause, self.infcx.param_env, ty, clone_trait);