pub fn on_msg(topic: String, message: Vec<u8>) {
println!("topic: {} message: {:?}", topic, message)
}
#[tokio::main]
async fn main() -> Result<(), String> {
let mut client = simple_pub_sub::client::Client::new("localhost".to_string(), 6480);
client.on_message(on_msg);
let _ = client.connect().await;
let _ = client.subscribe("abc".to_string()).await;
Ok(())
}