magento2/app/code/Magento/Customer/Controller/Adminhtml/Group.php

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Magento\Customer\Controller\Adminhtml;

use Magento\Customer\Api\Data\GroupInterfaceFactory;
use Magento\Customer\Api\GroupRepositoryInterface;

/**
 * Customer groups controller
 */
abstract class Group extends \Magento\Backend\App\Action
{
    /**
     * Authorization level of a basic admin session
     *
     * @see \Magento\Backend\App\Action\_isAllowed()
     */
    const ADMIN_RESOURCE = 'Magento_Customer::group';

    /**
     * Core registry
     *
     * @var \Magento\Framework\Registry
     */
    protected $_coreRegistry;

    /**
     * @var GroupRepositoryInterface
     */
    protected $groupRepository;

    /**
     * @var GroupInterfaceFactory
     */
    protected $groupDataFactory;

    /**
     * @var \Magento\Backend\Model\View\Result\ForwardFactory
     */
    protected $resultForwardFactory;

    /**
     * @var \Magento\Framework\View\Result\PageFactory
     */
    protected $resultPageFactory;

    /**
     * Initialize Group Controller
     *
     * @param \Magento\Backend\App\Action\Context $context
     * @param \Magento\Framework\Registry $coreRegistry
     * @param GroupRepositoryInterface $groupRepository
     * @param GroupInterfaceFactory $groupDataFactory
     * @param \Magento\Backend\Model\View\Result\ForwardFactory $resultForwardFactory
     * @param \Magento\Framework\View\Result\PageFactory $resultPageFactory
     */
    public function __construct(
        \Magento\Backend\App\Action\Context $context,
        \Magento\Framework\Registry $coreRegistry,
        GroupRepositoryInterface $groupRepository,
        GroupInterfaceFactory $groupDataFactory,
        \Magento\Backend\Model\View\Result\ForwardFactory $resultForwardFactory,
        \Magento\Framework\View\Result\PageFactory $resultPageFactory
    ) {
        $this->_coreRegistry = $coreRegistry;
        $this->groupRepository = $groupRepository;
        $this->groupDataFactory = $groupDataFactory;
        parent::__construct($context);
        $this->resultForwardFactory = $resultForwardFactory;
        $this->resultPageFactory = $resultPageFactory;
    }
}