shardtree: Add an accessor for a `ShardTree`'s underlying `ShardStore`

shardtree/CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to Rust's notion of
 
 ## Unreleased
 
+## Added
+* `Shardtree::store`
+
 ## [0.2.0] - 2023-11-07
 
 ## Added

shardtree/src/lib.rs

@@ -91,6 +91,11 @@ impl<
         self.store
     }
 
+    /// Returns a reference to the underlying [`ShardStore`].
+    pub fn store(&self) -> &S {
+        &self.store
+    }
+
     /// Returns the root address of the tree.
     pub fn root_addr() -> Address {
         Address::from_parts(Level::from(DEPTH), 0)