should be good to extend functionality now

src/balancer/mod.rs

@@ -0,0 +1,9 @@
+pub mod round_robin;
+
+use std::fmt::Debug;
+use std::sync::Arc;
+use crate::backend::Backend;
+
+pub trait Balancer: Debug + Send + Sync + 'static {
+    fn choose_backend(&mut self) -> Option<Arc<Backend>>;
+}