responsive_preview-8.x-1.0/modules/responsive_preview_navigation/responsive_preview_navigation.module

<?php

/**
 * Implements hook_theme().
 */
function responsive_preview_navigation_theme() {
  return [
    'responsive_preview_navigation' => [
      'variables' => [
        'items' => [],
        'attributes' => [],
      ],
    ],
  ];
}