isRenderCacheable example

'max-age' => $entity->getCacheMaxAge(),
      ],
    ];

    // Add the default #theme key if a template exists for it.     if ($this->themeRegistry->getRuntime()->has($this->entityTypeId)) {
      $build['#theme'] = $this->entityTypeId;
    }

    // Cache the rendered output if permitted by the view mode and global entity     // type configuration.     if ($this->isViewModeCacheable($view_mode) && !$entity->isNew() && $entity->isDefaultRevision() && $this->entityType->isRenderCacheable()) {
      $build['#cache'] += [
        'keys' => [
          'entity_view',
          $this->entityTypeId,
          $entity->id(),
          $view_mode,
        ],
        'bin' => $this->cacheBin,
      ];

      if ($entity instanceof TranslatableDataInterface && count($entity->getTranslationLanguages()) > 1) {
        

    $cache_tag = $this->entity->getCacheTags();
    $view_cache_tag = \Drupal::entityTypeManager()->getViewBuilder($entity_type)->getCacheTags();
    $render_cache_tag = 'rendered';

    $this->verifyPageCache($entity_url, 'MISS');

    // Verify a cache hit, but also the presence of the correct cache tags.     $this->verifyPageCache($entity_url, 'HIT');

    // Also verify the existence of an entity render cache entry, if this entity     // type supports render caching.     if (\Drupal::entityTypeManager()->getDefinition($entity_type)->isRenderCacheable()) {
      $cache_keys = ['entity_view', $entity_type, $this->entity->id(), $view_mode];
      $cid = $this->createCacheId($cache_keys, $entity_cache_contexts);
      $redirected_cid = NULL;
      $additional_cache_contexts = $this->getAdditionalCacheContextsForEntity($this->entity);
      if (count($additional_cache_contexts)) {
        $redirected_cid = $this->createCacheId($cache_keys, Cache::mergeContexts($entity_cache_contexts, $additional_cache_contexts));
      }
      $expected_cache_tags = Cache::mergeTags($cache_tag, $view_cache_tag);
      $expected_cache_tags = Cache::mergeTags($expected_cache_tags, $this->getAdditionalCacheTagsForEntity($this->entity));
      $expected_cache_tags = Cache::mergeTags($expected_cache_tags, [$render_cache_tag]);
      $this->verifyRenderCache($cid, $expected_cache_tags, $redirected_cid);
    }