Form.php

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

namespace Magento\Catalog\Block\Adminhtml;

use Magento\Backend\Block\Widget\Form\Generic;

/**
 * Base block for rendering category and product forms
 */
class Form extends Generic
{
    /**
     * Prepare the layout
     *
     * @return void
     */
    protected function _prepareLayout()
    {
        \Magento\Framework\Data\Form::setElementRenderer(
            $this->getLayout()->createBlock(
                \Magento\Backend\Block\Widget\Form\Renderer\Element::class,
                $this->getNameInLayout() . '_element'
            )
        );
        \Magento\Framework\Data\Form::setFieldsetRenderer(
            $this->getLayout()->createBlock(
                \Magento\Backend\Block\Widget\Form\Renderer\Fieldset::class,
                $this->getNameInLayout() . '_fieldset'
            )
        );
        \Magento\Framework\Data\Form::setFieldsetElementRenderer(
            $this->getLayout()->createBlock(
                \Magento\Catalog\Block\Adminhtml\Form\Renderer\Fieldset\Element::class,
                $this->getNameInLayout() . '_fieldset_element'
            )
        );
    }
}