diff --git a/examples/mratls_grpcs_server.rs b/examples/mratls_grpcs_server.rs
index b44d955..e922239 100644
--- a/examples/mratls_grpcs_server.rs
+++ b/examples/mratls_grpcs_server.rs
@@ -8,6 +8,7 @@ use hyper_util::{
     service::TowerToHyperService,
 };
 use pb::{EchoRequest, EchoResponse};
+use std::io::Write;
 use std::sync::Arc;
 use tokio::net::TcpListener;
 use tokio_rustls::{
@@ -37,6 +38,10 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, format!("{}", e)))?;
     tls.alpn_protocols = vec![b"h2".to_vec()];
 
+    // create and write a file on the disk
+    let mut file = std::fs::File::create("test.txt")?;
+    file.write_all(b"Hello, world!")?;
+
     let server = EchoServer::default();
 
     let svc = Routes::new(pb::echo_server::EchoServer::new(server)).prepare();