/** Print plugins information. */
  private void ackPluginsInfo() {
    U.quietAndInfo(log, "Configured plugins:");

    if (plugins.isEmpty()) {
      U.quietAndInfo(log, "  ^-- None");
      U.quietAndInfo(log, "");
    } else {
      for (PluginProvider plugin : plugins.values()) {
        U.quietAndInfo(log, "  ^-- " + plugin.name() + " " + plugin.version());
        U.quietAndInfo(log, "  ^-- " + plugin.copyright());
        U.quietAndInfo(log, "");
      }
    }
  }