You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: regex.rs
    path of file: ./repos/materialize/src/repr/src/adt
    
    the code of the file until where you have to start completion: // Copyright Materialize, Inc. and contributors. All rights reserved.
//
// Use of this software is governed by the Business Source License
// included in the LICENSE file.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of this software will be governed
// by the Apache License, Version 2.0.

//! Regular exp
    
    fn regex_serde_case_insensitive() {
        let orig_regex = Regex::new("AAA".to_string(), true).unwrap();
        let serialized: String = serde_json::to_string(&orig_regex).unwrap();
        let roundtrip_result: Regex = serde_json::from_str(&serialized).unwrap();
        // Equality test between orig and roundtrip_result wouldn't work, because Eq doesn't test
        // the actual regex object. So test the actual regex functionality (concentrating on case
        // sensitivity).
        assert_eq!(orig_regex.regex.is_match("aaa"), true);
        assert_eq!(roundtrip_result.regex.is_match("aaa"), true);
    }