private AbstractChatTab addAndGetChannelTab(String playerOrChannelName) {
    JavaFxUtil.assertApplicationThread();

    if (!nameToChatTab.containsKey(playerOrChannelName)) {
      AbstractChatTab tab = chatTabFactory.createChannelTab(playerOrChannelName);
      addTab(playerOrChannelName, tab);
    }
    return nameToChatTab.get(playerOrChannelName);
  }
  private AbstractChatTab addAndGetPrivateMessageTab(String username) {
    JavaFxUtil.assertApplicationThread();

    if (!nameToChatTab.containsKey(username)) {
      AbstractChatTab tab = chatTabFactory.createPrivateMessageTab(username);
      addTab(username, tab);
    }

    return nameToChatTab.get(username);
  }