use tokio::net::TcpListener;

 use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};

 #[tokio::main]

 async fn main() {

   tracing_subscriber::registry()

     .with(

       tracing_subscriber::EnvFilter::try_from_default_env()

         .unwrap_or_else(|_| "demo_service=debug".into()),

     )

     .with(tracing_subscriber::fmt::layer())

     .init();

   let listener = TcpListener::bind("127.0.0.1:8888").await.unwrap();

   tracing::debug!("listening on {}", listener.local_addr().unwrap());

 }