public static void handlePlayerPreLogin(AsyncPlayerPreLoginEvent event) {
    final String ip = event.getAddress().getHostAddress().trim();
    final boolean isAdmin = TFM_AdminList.isSuperAdminSafe(null, ip);

    // Check if the player is already online
    for (Player onlinePlayer : TotalFreedomMod.server.getOnlinePlayers()) {
      if (!onlinePlayer.getName().equalsIgnoreCase(event.getName())) {
        continue;
      }

      if (!isAdmin) {
        event.disallow(
            AsyncPlayerPreLoginEvent.Result.KICK_OTHER,
            "Your username is already logged into this server.");
      } else {
        event.allow();
        TFM_Sync.playerKick(
            onlinePlayer, "An admin just logged in with the username you are using.");
      }
      return;
    }
  }