newsupernova/app/code/Magefan/Blog/Block/Adminhtml/Post/Edit/Form.php

<?php
/**
 * Copyright © 2015 Ihor Vansach (ihor@magefan.com). All rights reserved.
 * See LICENSE.txt for license details (http://opensource.org/licenses/osl-3.0.php).
 *
 * Glory to Ukraine! Glory to the heroes!
 */

namespace Magefan\Blog\Block\Adminhtml\Post\Edit;

/**
 * Adminhtml cms page edit form block
 *
 * @author      Magento Core Team <core@magentocommerce.com>
 */
class Form extends \Magento\Backend\Block\Widget\Form\Generic
{
    /**
     * Prepare form
     *
     * @return $this
     */
    protected function _prepareForm()
    {
        /** @var \Magento\Framework\Data\Form $form */
        $form = $this->_formFactory->create([
            'data' => [
                'id' => 'edit_form',
                'action' => $this->getData('action'),
                'method' => 'post',
                'enctype' => 'multipart/form-data',
            ]
        ]);
        $form->setUseContainer(true);
        $this->setForm($form);
        return parent::_prepareForm();
    }
}