diff --git a/tonic-build/src/service.rs b/tonic-build/src/service.rs
index cbad4a7..a605ca5 100644
--- a/tonic-build/src/service.rs
+++ b/tonic-build/src/service.rs
@@ -214,7 +214,6 @@ fn generate_unary(
             Ok(res)
         };
 
-        // TODO: implement this future manually
         Box::pin(fut)
     }
 }
diff --git a/tonic/src/transport/server.rs b/tonic/src/transport/server.rs
index 22bec87..2daba61 100644
--- a/tonic/src/transport/server.rs
+++ b/tonic/src/transport/server.rs
@@ -38,6 +38,7 @@ impl Server {
 pub struct Builder {
     tls: Option<(Vec<u8>, Vec<u8>)>,
     interceptor: Option<Interceptor>,
+    // concurrency_limit: Option<usize>,
 }
 
 impl Builder {
@@ -50,7 +51,10 @@ impl Builder {
         self
     }
 
+    // FIXME: add server side layering ability
     // pub fn concurrency_limit(&mut self, limit: usize) -> &mut Self {
+    //     self.concurrency_limit = Some(limit);
+    //     self
     // }
 
     pub fn interceptor_fn<F, Out>(&mut self, f: F) -> &mut Self