private String MapDebug_Log() {
        final StringBuilder sb = new StringBuilder("Defeat time : ");
        sb.append(FileoutputUtil.CurrentReadable_Time());

        sb.append(" | Mapid : ").append(this.mapid);

        charactersLock.readLock().lock();
        try {
            sb.append(" Users [").append(characters.size()).append("] | ");
            for (MapleCharacter mc : characters) {
                sb.append(mc.getName()).append(", ");
            }
        } finally {
            charactersLock.readLock().unlock();
        }
        return sb.toString();
    }