{"ast_node_type":"other","tokens":[{"end":56,"kind":"keyword","start":0,"text":".and_then(|match_expr|"}]}
                                .and_then(|match_expr| {
                                .and_then(ast::MatchExpr::cast)
                                    let expr_opt = find_opt_node_in_file(original_file, match_expr.expr());