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: settings.rs
    path of file: ./repos/qdrant/src
    
    the code of the file until where you have to start completion: use std::{env, io};

use api::grpc::transport_channel_pool::{
    DEFAULT_CONNECT_TIMEOUT, D
    
    fn test_runtime_development_config() {
        env::set_var("RUN_MODE", "development");

        // `sealed_test` copies files into the same directory as the test runs in.
        // We need them in a subdirectory.
        std::fs::create_dir("config").expect("failed to create `config` subdirectory.");
        std::fs::copy("config.yaml", "config/config.yaml").expect("failed to copy `config.yaml`.");
        std::fs::copy("development.yaml", "config/development.yaml")
            .expect("failed to copy `development.yaml`.");

        // Read config
        let config = Settings::new(None).expect("failed to load development config at runtime");

        // Validate
        config
            .validate()
            .expect("failed to validate development config at runtime");
        assert!(config.load_errors.is_empty(), "must not have load errors")
    }