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: action_cache_tests.rs
    path of file: ./repos/pants/src/rust/engine/remote_provider/remote_provider_reapi/src
    
    the code of the file until where you have to start completion: // Copyright 2023 Pants project contributors (see CONTRIBUTORS.md).
// Licensed under the Apache License, Version 2.0 
    
async fn get_action_result_existing() {
    let cas = StubCAS::empty();
    let provider = new_provider(&cas).await;

    let action_digest = Digest::of_bytes(b"get_action_cache test");
    let action_result = remexec::ActionResult {
        exit_code: 123,
        ..Default::default()
    };
    cas.action_cache
        .action_map
        .lock()
        .insert(action_digest.hash, action_result.clone());

    assert_eq!(
        provider.get_action_result(action_digest, "").await,
        Ok(Some(action_result))
    );
}