Magento 2 : Add WYSISYG Editor Admin Form In Custom Module

<?php
namespace [VENDOR]\[EXTENSION]\Block\Adminhtml\[CUSTOM]\Edit\Tab;

class Form extends \Magento\Backend\Block\Widget\Form\Generic implements \Magento\Backend\Block\Widget\Tab\TabInterface
{
protected $_wysiwygConfig;

public function __construct(
\Magento\Backend\Block\Template\Context $context,
\Magento\Framework\Registry $registry,
\Magento\Framework\Data\FormFactory $formFactory, 
\Magento\Cms\Model\Wysiwyg\Config $wysiwygConfig,
array $data = []
)
{
$this->_wysiwygConfig = $wysiwygConfig;
parent::__construct($context, $registry, $formFactory, $data);
}

protected function _prepareForm()
{
$model = $this->_coreRegistry->registry('EXTENSIONKEY');

/** @var \Magento\Framework\Data\Form $form */
$form = $this->_formFactory->create();

$fieldset = $form->addFieldset('base_fieldset', ['legend' => __('YOUR FORM TITLE')]);

$fieldset->addField('storycontent', 'editor', [
  'name'      => 'storycontent',
  'label'   => 'Story Content',
  'config'    => $this->_wysiwygConfig->getConfig(),
  'wysiwyg'   => true,
  'required'  => false,
  'after_element_html' => '<small>YOURCOMMENT.</small>',
  'value' => $model->getStorycontent()
]);

$this->setForm($form);
return parent::_prepareForm();
}
}
?>