#vulnerable code 
                             @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
	public void onInventoryClick(InventoryClickEvent event) {
		if (event.getInventory().getType() != InventoryType.BREWING || event.getAction() == InventoryAction.NOTHING
				|| event.getClick() == ClickType.NUMBER_KEY && event.getAction() == InventoryAction.HOTBAR_MOVE_AND_READD
				|| !isBrewablePotion(event)) {
			return;
		}

		Player player = (Player) event.getWhoClicked();
		int eventAmount = event.getCurrentItem().getAmount();
		if (event.isShiftClick()) {
			eventAmount = Math.min(eventAmount, inventoryHelper.getAvailableSpace(player, event.getCurrentItem()));
			if (eventAmount == 0) {
				return;
			}
		}

		updateStatisticAndAwardAchievementsIfAvailable(player, eventAmount, event.getRawSlot());
	} 
                            #location 10 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
	public void onInventoryClick(InventoryClickEvent event) {
		ItemStack item = event.getCurrentItem();
		if (event.getInventory().getType() != InventoryType.BREWING || event.getAction() == InventoryAction.NOTHING
				|| event.getClick() == ClickType.NUMBER_KEY && event.getAction() == InventoryAction.HOTBAR_MOVE_AND_READD
				|| !isBrewablePotion(item)) {
			return;
		}

		Player player = (Player) event.getWhoClicked();
		int eventAmount = item.getAmount();
		if (event.isShiftClick()) {
			eventAmount = Math.min(eventAmount, inventoryHelper.getAvailableSpace(player, item));
			if (eventAmount == 0) {
				return;
			}
		}

		updateStatisticAndAwardAchievementsIfAvailable(player, eventAmount, event.getRawSlot());
	}