code: protected DefaultServerDolphin createServerDolphin() {
          ServerModelStore modelStore = createServerModelStore();
          ServerConnector connector = createServerConnector(modelStore, createCodec());
          return new DefaultServerDolphin(modelStore, connector);
      }
docs: Creates a new instance of {@code DefaultServerDolphin}.
  Subclasses may override this method to customize how this instance should be created.
  
  @return a newly created {@code DefaultServerDolphin}.