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: region_migration.rs
    path of file: ./repos/greptimedb/src/meta-srv/src/procedure
    
    the code of the file until where you have to start completion: // Copyright 2023 Greptim
    
    fn test_lock_key() {
        let persistent_context = new_persistent_context();
        let expected_keys = persistent_context.lock_key();

        let env = TestingEnv::new();
        let context = env.context_factory();

        let procedure = RegionMigrationProcedure::new(persistent_context, context);

        let key = procedure.lock_key();
        let keys = key.keys_to_lock().cloned().collect::<Vec<_>>();

        for key in expected_keys {
            assert!(keys.contains(&key));
        }
    }