{"ast_node_type":"variable","tokens":[{"end":54,"kind":"keyword","start":0,"text":"let"}]}
        let operand = self.collect_expr_opt(e.expr());
        let try_from_residual = self.lang_path(LangItem::TryTraitFromResidual);
        let try_branch = self.alloc_expr(try_branch.map_or(Expr::Missing, Expr::Path), syntax_ptr);