message: Unnecessary key clone
diff: @@ -351,7 +351,6 @@ impl MerkleStorage {
  }
  self.set_exec_times += 1;
  rv
  -
  }
  /// Delete an item from the staging area.
  @@ -625,7 +624,7 @@ impl MerkleStorage {
  }
  fn key_to_string(&self, key: &ContextKey) -> String {
  - key.clone().join("/")
  + key.join("/")
  }
  fn string_to_key(&self, string: &str) -> ContextKey {
  