onAfterOrderUpdate custom plugin

public function onAfterOrderCreate(&$order, &$send_email) {
		
		$app = JFactory::getApplication();
		
		if($app->isAdmin())
		{
			
			return true;
		
		}
		
		if(!isset($order->order_status))
		{
			
			return true;
			
		}
		
		if(!empty($order->order_type) && $order->order_type != 'sale')
		{
			
			return true;
			
		}
		
		$this->awardDonationRewards($order);
		
		unset($this->fullOrder);
		
		return true;
	
	}

public function onAfterOrderUpdate(&$order, &$send_email) {
		
		echo 'success';
		jexit();
}

public function onAfterOrderUpdate($order, $send_email)
	{
		// Only process PayPal orders
		if ($order->order_payment_id != 1) return;
		
		$orderFile = $this->params->get('path') . '/infounit_export_orders.csv';
		// Only run if there are orders waiting to be imported
		if (!is_file($orderFile)) return;
		
		$newRows = [];
		// Read CSV
		if (($stream = fopen($orderFile, 'r')) !== false)
		{
			$index = 0;
			$indexZahlungsweg;
			$indexBestellzeichen;
			while (($row = fgetcsv($stream, 1000, ';')) !== false)
			{
				// Look up which column contains the payment information and which column contains the order number
				if ($index == 0)
				{
					$indexZahlungsweg = array_search('Zahlungsweg', $row);
					$indexBestellzeichen = array_search('Bestellzeichen', $row);
				}
				
				// Use the order number to find the right order
				if ($row[$indexBestellzeichen] == $order->order_number)
				{
					// Update the order status
					switch ($order->order_status)
					{
						case 'confirmed':
						$row[$indexZahlungsweg] = 'PayPal';
						break;
						case 'cancelled':
						$row[$indexZahlungsweg] = 'PayPal (storniert!)';
						break;
						case 'created':
						$row[$indexZahlungsweg] = 'PayPal (nicht bezahlt!)';
						break;
					}
				}
				$newRows[] = $row;
				$index++;
			}
			fclose($stream);
		}
		
		// Write back to CSV
		if (($stream = fopen($orderFile, 'w')) !== false)
		{
			foreach($newRows as $row)
			{
				fputcsv($stream, $row, ';');
			}
			fclose($stream);
		}
	}