message: Adding friendly comment about return value
diff: @@ -57,6 +57,7 @@ public:
  static void ReplacementOpenPost(ClientContext &context, const string &extension, DatabaseInstance &instance,
  ReplacementOpenData *open_data);
  + // Returns extension name, or empty string if not a replacement open path
  static string ExtractExtensionPrefixFromPath(const string &path);
  private:
  