public JBCefClient add(@NotNull T handler, @NotNull CefBrowser browser, @NotNull Runnable onInit) {
      if (myMap == null) {
        syncInitMap();
      }
      List<T> list = myMap.get(browser);
      if (list == null) {
        list = syncInitList(browser, onInit);
      }
      list.add(handler);
      return JBCefClient.this;
    }
public JBCefClient add(@NotNull T handler, @NotNull CefBrowser browser, @NotNull Runnable onInit)