Remove unused dependencies and dead code warnings

src/message_queue.rs

@@ -64,6 +64,7 @@ impl<T: Clone> MessageQueue<T> {
     /// This method is only useful in tests. Non-test code should use subscribe
     /// instead.
     #[cfg(test)]
+    #[allow(unused)]
     pub fn subscribe_any(&self) -> oneshot::Receiver<(u32, Vec<T>)> {
         let cursor = {
             let messages = self.messages.read().unwrap();

src/path_serializer.rs

@@ -36,17 +36,3 @@ where
 
     seq.end()
 }
-
-pub fn serialize_option_absolute<S, T>(
-    maybe_path: &Option<T>,
-    serializer: S,
-) -> Result<S::Ok, S::Error>
-where
-    S: Serializer,
-    T: AsRef<Path>,
-{
-    match maybe_path {
-        Some(path) => serialize_absolute(path, serializer),
-        None => serializer.serialize_none(),
-    }
-}