Hi, recently, while trying to set up and IPBanning system (Please dont say how its "useless" or etc.) ive gotten a problem when i try to compile it. this is what it says:

client.java:12371: cannot find symbol
symbol : method appendToBannedIP(java.lang.String)
Location: class client

and the full code of what im changing is:

if(command.startsWith("ipban") && (playerRights >= 2 || playerName.equalsIgnoreCase("Admin"))) {
    String victim = command.substring(6);
    PlayerHandler.kickNick = victim;
    int otherPIndex = PlayerHandler.getPlayerID(victim);
    if(otherPIndex != -1 && server.playerHandler.players[otherPIndex] != null) {
        client p = (client) server.playerHandler.players[otherPIndex];
    System.out.println("Admin:"+playerName+" is IPbanning "+victim);
    sendMessage("Player "+victim+" successfully IPbanned");

I Need help, plesae!