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: lib.rs
    path of file: ./repos/libsql/libsql-sqlite3/test/rust_suite/src
    
    the code of the file until where you have to start completion: #[cfg(test)]
mod alter_column;
mod random_rowid;
mod virtual_wal;
#[cfg(all(test, feature = "extensions"))]
mod extensions;

#[cfg(all(test, feature = "udf"))]
mod user_defined_functions;
#[cfg(all(test, feature = "udf"))]
mod user_defined_functions_src;

#[cfg(test)]
mod tests {
    extern "C" {
        fn libsql_close_hook(
            db: *mut libsql_sys::ffi::sqlite3,
            callback: Option<
                extern "C" fn(arg: *mut std::ffi::c_void, db: *mut libsql_sys::ffi::sqlite3),
  
    
    fn test_close_hook() {
        let conn = Connection::open_in_memory().unwrap();
        let mut closed = false;

        extern "C" fn cb(closed: *mut c_void, _db: *mut libsql_sys::ffi::sqlite3) {
            unsafe {
                println!("Close hook called!");
                let closed = &mut *(closed as *mut bool);
                *closed = true;
            }
        }
        unsafe {
            libsql_close_hook(conn.handle(), Some(cb), &mut closed as *mut _ as *mut _);
        }
        assert!(!closed);
        drop(conn);
        assert!(closed);
    }