nit

crates/chain-state/src/in_memory.rs

@@ -104,7 +104,7 @@ impl InMemoryState {
     /// Returns the current chain head state.
     pub(crate) fn head_state(&self) -> Option<Arc<BlockState>> {
         let hash = *self.numbers.read().last_key_value()?.1;
-        self.blocks.read().get(&hash).cloned()
+        self.state_by_hash(hash)
     }
 
     /// Returns the pending state corresponding to the current head plus one,