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: mod.rs
    path of file: ./repos/rdms/src/wral
    
    the code of the file until where you have to start completion: //! Module implement Write-Ahead-Logging.
//!
//! Write-Ahead-Logging is implemented by [Wal] type. To get started create
//! first a configuration [Config] value. Subsequently, a fresh Wal instanc
    
    fn arbitrary(u: &mut arbitrary::Unstructured) -> arbitrary::Result<Self> {
        use std::env;

        let name: String = u.arbitrary()?;
        let dir = env::temp_dir().into_os_string();

        let journal_limit = *u.choose(&[100, 1000, 10_000, 1_000_000])?;
        let fsync: bool = u.arbitrary()?;

        let config = Config { name, dir, journal_limit, fsync };
        Ok(config)
    }