diff --git a/tower/src/balance.rs b/tower/src/balance.rs
index 6fa7fad..fe720e8 100644
--- a/tower/src/balance.rs
+++ b/tower/src/balance.rs
@@ -74,6 +74,7 @@ impl Builder {
     {
         let d: PoolDiscoverer<MS, Target, Request> = todo!();
 
+        // THE CRITICAL STATEMENT
         let x = Balance::new(Box::pin(d));
 
         todo!()
@@ -116,5 +117,4 @@ impl<Request, Svc: Service<Request>> Service<Request> for DropNotifyService<Svc>
     type Response = Svc::Response;
     type Future = Svc::Future;
     type Error = Svc::Error;
-
 }
diff --git a/tower/src/lib.rs b/tower/src/lib.rs
index bd87523..769ec9a 100644
--- a/tower/src/lib.rs
+++ b/tower/src/lib.rs
@@ -40,14 +40,9 @@ where
 pub struct Change<K, V>(K, V);
 
 pub trait Service<Request> {
-    /// Responses given by the service.
     type Response;
-
-    /// Errors produced by the service.
     type Error;
-
-    /// The future response value.
-    type Future: Future<Output = Result<Self::Response, Self::Error>>;
+    type Future;
 }
 
 pub trait MakeService<Target, Request> {