this.hiddenSlots.put(slot, hiddenSlot);
this.hiddenSlots.add(hiddenSlot);
    public void addHiddenSlot(String slot, boolean multiple, String value, Class<Converter> converter) {        HiddenSlot hiddenSlot = this.hiddenSlots.get(slot);                if (hiddenSlot == null) {            hiddenSlot = new HiddenSlot(slot, value, converter);                        this.hiddenSlots.put(slot, hiddenSlot);        }        else {            hiddenSlot.addValue(value);        }                hiddenSlot.setConverter(converter);        hiddenSlot.setMultiple(hiddenSlot.isMultiple() || multiple);    }