Q:

Magento 2 : Face Error while create a custom block

I got the below error when create the Custom Block for the HTML sitemap.

Error filtering template: Warning: Declaration of
  Vapor\Sitemap\Block\Sitemap\Category::_getHtml(Magento\Framework\Data\Tree\Node
  $menuTree, $childrenWrapClass, $limit, $colBrakes = Array) should be
  compatible with
  Magento\Theme\Block\Html\Topmenu::_getHtml(Magento\Framework\Data\Tree\Node
  $menuTree, $childrenWrapClass, $limit, array $colBrakes = Array) in
  C:\xampp\htdocs\Magento\app\code\Vapor\Sitemap\Block\Sitemap\Category.php
  on line 62

Block Code 
<?php
namespace Vapor\Sitemap\Block\Sitemap;
// use Magento\Framework\View\Element\Template\Context;
use Magento\Framework\View\Element\Template;
// use Vapor\Sitemap\Model\Sitemap\CmsPages;
// use Vapor\Sitemap\Block\Sitemap\Cms;
// use Vapor\Sitemap\Block\Sitemap\Category;
class Index extends Template
{
    const SITEMAP_CUSTOM_TEMPLATE = 'Vapor_Sitemap::sitemap/sitemap.phtml';

    /**
     * [__construct]
     * @param \Magento\Framework\View\Element\Template\Context $context
     * @param \Magento\Framework\Stdlib\DateTime\Timezone      $_stdTimezone [description]
     * @param array $data
     */
    protected $getSitemap;

    public function __construct(\Magento\Framework\View\Element\Template\Context $context,\Magento\Framework\Stdlib\DateTime\Timezone $_stdTimezone,
        array $data = [])
    {
        parent::__construct($context, $data);
        $this->getSitemap();

    }

    /**
     * 
     * @return html
     */
    protected function _toHtml()
    { 
        return parent::_toHtml();
    }
    /**
     * @return Mixed data
     */
    public function getSitemap()
    {
        //echo "ComeHere";exit;
        $this->setTemplate(self::SITEMAP_CUSTOM_TEMPLATE);
        return $this;
    }
}

Can anyone help to solve this.
Any help would be appreciated.
Thanks in advance..! 

A:

make your _getHtml method from the class Vapor\Sitemap\Block\Sitemap\Category look like this:
protected function _getHtml(
    \Magento\Framework\Data\Tree\Node $menuTree,
    $childrenWrapClass,
    $limit,
    array $colBrakes = []
) {
.....
}

you are missing a type hint array on the last parameter

