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/lagon/crates/serverless_logger/src
    
    the code of the file until where you have to start completion: use axiom_rs::Client;
use chrono::prelude::Local;
use flume::Sender;
use log::{
    as_serde, kv::source::as_map, set_boxed_logger, set_max_level, Level, LevelFilter, Log,
    Metadata, Record, SetLoggerError,
};
use serde_json::{json, Value};
use std::sync::{Arc, RwLock};

struct SimpleLogger {
    tx: Arc<RwLock<Option<Sender<Value>>>>,
    region: String,
}

impl SimpleLogger {
    pub fn new(region: String) -> Self {
        let (tx, rx) = flume::unbounded();

        // Axiom is opti
    
    pub fn new(region: String) -> Self {
        let (tx, rx) = flume::unbounded();

        // Axiom is optional
        match Client::new() {
            Ok(axiom_client) => {
                tokio::spawn(async move {
                    if let Err(error) = axiom_client
                        .ingest_stream("serverless", rx.into_stream())
                        .await
                    {
                        eprintln!("Error ingesting into Axiom: {error}");
                    }
                });
            }
            Err(error) => println!("Axiom is not configured: {error}"),
        }

        Self {
            tx: Arc::new(RwLock::new(Some(tx))),
            region,
        }
    }