magento 2.4.2 showing Undefined property $appEmulation when I create pdf invoice preference

[webkeonsanjeev]

I have created preference for Magento\Sales\Model\Order\Pdf\Invoice file inside preference Invoice class I overwrite getPdf function but it is showing below error

Exception #0 (Exception): Notice: Undefined property: Webkeon\Custompdf\Model\Order\Pdf\Invoice::$appEmulation

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Webkeon\Custompdf\Model\Order\Pdf;


/**
 * Sales Order Invoice PDF model
 * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
 */
class Invoice extends \Magento\Sales\Model\Order\Pdf\Invoice 
{
	
    /**
     * Draw header for item table
     *
     * @param \Zend_Pdf_Page $page
     * @return void
     */
    protected function _drawHeader(\Zend_Pdf_Page $page)
    {
        /* Add table head */
        $this->_setFontRegular($page, 10);
        $page->setFillColor(new \Zend_Pdf_Color_Rgb(0.93, 0.92, 0.92));
        $page->setLineColor(new \Zend_Pdf_Color_GrayScale(0.5));
        $page->setLineWidth(0.5);
        $page->drawRectangle(25, $this->y, 570, $this->y - 15);
        $this->y -= 10;
        $page->setFillColor(new \Zend_Pdf_Color_Rgb(0, 0, 0));

        //columns headers
        $lines[0][] = ['text' => __('Products'), 'feed' => 35];

        //$lines[0][] = ['text' => __('SKU'), 'feed' => 290, 'align' => 'right'];

        $lines[0][] = ['text' => __('Qty'), 'feed' => 435, 'align' => 'right'];

        $lines[0][] = ['text' => __('Price'), 'feed' => 360, 'align' => 'right'];

        $lines[0][] = ['text' => __('Tax'), 'feed' => 495, 'align' => 'right'];

        $lines[0][] = ['text' => __('Subtotal'), 'feed' => 565, 'align' => 'right'];

        $lineBlock = ['lines' => $lines, 'height' => 5];

        $this->drawLineBlocks($page, [$lineBlock], ['table_header' => true]);
        $page->setFillColor(new \Zend_Pdf_Color_GrayScale(0));
        $this->y -= 20;
    }

    /**
     * Return PDF document
     *
     * @param array|Collection $invoices
     * @return \Zend_Pdf
     */
    public function getPdf($invoices = [])
    {
        $this->_beforeGetPdf();
        $this->_initRenderer('invoice');

        $pdf = new \Zend_Pdf();
        $this->_setPdf($pdf);
        $style = new \Zend_Pdf_Style();
        $this->_setFontBold($style, 10);

        foreach ($invoices as $invoice) {
            if ($invoice->getStoreId()) {
                $this->appEmulation->startEnvironmentEmulation(
                    $invoice->getStoreId(),
                    \Magento\Framework\App\Area::AREA_FRONTEND,
                    true
                );
                $this->_storeManager->setCurrentStore($invoice->getStoreId());
            }
            $page = $this->newPage();
            $order = $invoice->getOrder();
			$this->y = 730;
            /* Add image */
            //$this->insertLogo($page, $invoice->getStore());
            /* Add address */
           // $this->insertAddress($page, $invoice->getStore());
            /* Add head */
            $this->insertOrder(
                $page,
				$invoice,
                $order,
                $this->_scopeConfig->isSetFlag(
                    self::XML_PATH_SALES_PDF_INVOICE_PUT_ORDER_ID,
                    \Magento\Store\Model\ScopeInterface::SCOPE_STORE,
                    $order->getStoreId()
                )
            );
				$this->y -= 50;
            /* Add document text and number */
			
            $this->insertDocumentNumber($page, __('Invoice # ') . $invoice->getIncrementId());
            /* Add table */
            $this->_drawHeader($page);
            /* Add body */
            foreach ($invoice->getAllItems() as $item) {
                if ($item->getOrderItem()->getParentItem()) {
                    continue;
                }
                /* Draw item */
                $this->_drawItem($item, $page, $order);
                $page = end($pdf->pages);
            }
            /* Add totals */
            $this->insertTotals($page, $invoice);
            if ($invoice->getStoreId()) {
                $this->appEmulation->stopEnvironmentEmulation();
            }
        }
        $this->_afterGetPdf();
        return $pdf;
    }

    
}