Unhandled exception executing command 'fakechest' in fakechest: Cannot instantiate abstract class

Error

PHP:

[13:41:00] [Server thread/CRITICAL]: Unhandled exception executing command 'fakechest' in fakechest: Cannot instantiate abstract class FakeChest\Inventory\WindowInventory    
[13:41:00] [Server thread/CRITICAL]: Error: "Cannot instantiate abstract class FakeChest\Inventory\WindowInventory" (EXCEPTION) in "VitualChest/src/FakeChest/Loader" at line 229


Line: 299
$chest = new WindowInventory($player, 27, "§8-=>[§dFake §eAChest§8]=-");

 

http://bfy.tw/F1c6
https://stackoverflow.com/a/44219467

 

I must either explicitly redefine the abstract methods of the superclass or make our WindowInventory class abstract.
But

PHP:

<?php

namespace FakeChest\Inventory;

use pocketmine\block\Block;
use pocketmine\inventory\CustomInventory;
use pocketmine\Player;
use pocketmine\math\Vector3;
use pocketmine\inventory\InventoryType;
use pocketmine\network\protocol\UpdateBlockPacket;
use pocketmine\nbt\tag\CompoundTag;
use pocketmine\nbt\tag\StringTag;
use pocketmine\tile\Tile;
use pocketmine\nbt\tag\IntTag;
use pocketmine\nbt\NBT;
use pocketmine\network\protocol\BlockEntityDataPacket;
use pocketmine\inventory\InventoryHolder;

abstract  class WindowInventory extends CustomInventory{

    protected $customName = "";
    protected $tile;
    protected $block;

    public function __construct(Player $player, $size = 27, $name = "") {
        $this->tile = Tile::CHEST;
        $this->block = 54;
        $type = InventoryType::get(InventoryType::CHEST);
        switch($size){
            case 5:
                $this->tile = Tile::HOPPER;
                $this->block = 154;
                $type = InventoryType::get(InventoryType::HOPPER);
                break;
            case 9:
                $this->tile = Block::WORKBENCH;
                $this->block = 58;
                $type = InventoryType::get(InventoryType::WORKBENCH);
                break;
            case 27:
                $type = InventoryType::get(InventoryType::CHEST);
                $this->tile = Tile::CHEST;
                $this->block = 54;
                break;
            case 2:
                $type = InventoryType::get(InventoryType::ENCHANT_TABLE);
                $this->tile = Tile::ENCHANT_TABLE;
                $this->block = 116;
                break;
            case 3:
                $type = InventoryType::get(InventoryType::FURNACE);
                $this->tile = Tile::FURNACE;
                $this->block = 61;
                break;
            case 1:
                $type = InventoryType::get(InventoryType::BREWING_STAND);
                $this->tile = Tile::BREWING_STAND;
                $this->block = 117;
                break;
            default:
                $player->getServer()->getLogger()->notice("Unknown window size. If must be one from: 1, 2, 3, 5, 9, 27, 54. Using default size(27).");
        }
        $this->customName = $name;
        $holder = new WindowHolder($player->getFloorX(), $player->getFloorY() + 2, $player->getFloorZ(), $this);
        parent::__construct($holder, $type);
    }

    public function onOpen(Player $who): void {
        $this->holder = $holder = new WindowHolder($who->getFloorX(), $who->getFloorY() + 2, $who->getFloorZ(), $this);
        $pk = new UpdateBlockPacket();
        $pk->x = $holder->x;
        $pk->y = $holder->y;
        $pk->z = $holder->z;
        $pk->blockId = $this->block;
        $pk->blockData = 0;
        $pk->flags = UpdateBlockPacket::FLAG_ALL;
        $who->dataPacket($pk);
        $c = new CompoundTag("", [
            new StringTag("id", $this->tile),
            new IntTag("x", (int) $holder->x),
            new IntTag("y", (int) $holder->y),
            new IntTag("z", (int) $holder->z)
        ]);
        if($this->name !== ""){
            $c->CustomName = new StringTag("CustomName", $this->customName);
        }
        $nbt = new NBT(NBT::LITTLE_ENDIAN);
        $nbt->setData($c);
        $pk = new BlockEntityDataPacket();
        $pk->x = $holder->x;
        $pk->y = $holder->y;
        $pk->z = $holder->z;
        $pk->namedtag = $nbt->write();
        $who->dataPacket($pk);
        parent::onOpen($who);
        $this->sendContents($who);
    }

    public function onClose(Player $who): void {
        $holder = $this->holder;
        $pk = new UpdateBlockPacket();
        $pk->x = $holder->x;
        $pk->y = $holder->y;
        $pk->z = $holder->z;
        $pk->blockId = $who->getLevel()->getBlockIdAt($holder->x, $holder->y, $holder->z);
        $pk->blockData = $who->getLevel()->getBlockDataAt($holder->x, $holder->y, $holder->z);
        $pk->flags = UpdateBlockPacket::FLAG_ALL;
        $who->dataPacket($pk);
        parent::onClose($who);
    }
}

 

just make your class a normal class instead of it being abstract. Otherwise, you need to create another class which extends from your abstract class and is not abstract itself