Implement Python bindings for IndexedQueue

src/backing/indexed/binary_heap.rs

@@ -50,4 +50,8 @@ impl<D: Hash + Clone + Send + Sync, P: PartialOrd + Clone + Send + Sync> Indexed
     fn remove(&mut self, data: D) -> bool {
         todo!()
     }
+
+    fn contains(&self, data: &D) -> bool {
+        todo!()
+    }
 }

src/backing/indexed/mod.rs

@@ -13,4 +13,6 @@ pub trait IndexedBacking<D: Clone + Send + Sync, P: PartialOrd + Clone + Send +
     fn update(&mut self, data: D, priority: P) -> bool;
     /// Remove an item from the queue
     fn remove(&mut self, data: D) -> bool;
+    /// Check if an item is already in the queue
+    fn contains(&self, data: &D) -> bool;
 }