template integration according to documentation!

I follow the below instruction according to document in module but not possible to get
panels_everywhere_site_template in reference variable.... hence the template not executing!

You can also give your theme a hybrid mode where it will be smart and use its
normal page.tpl.php if the site_template is not in use, and use a stripped
down page.tpl.php if it is. Place the following code in your theme (chances
are you already have a preprocess page).

  function MYTHEME_preprocess_page(&$vars) {
    if (!empty($vars['panels_everywhere_site_template'])) {
      $vars['template_file'] = 'page-panels-everywhere';
    }
  }

Please let me know if any alternative solution of this