{"ast_node_type":"variable","tokens":[{"end":82,"kind":"keyword","start":0,"text":"let"}]}
            let mut deferred_cast_checks = self.deferred_cast_checks.borrow_mut();
            // Defer other checks until we're done type checking.
            match cast::CastCheck::new(self, e, t_expr, t_cast, t.span, expr.span) {