getAdditionalCacheContextsForEntityListing example

// Verify a cache hit, but also the presence of the correct cache tags.     $expected_tags = Cache::mergeTags($referencing_entity_cache_tags, $page_cache_tags);
    $expected_tags = Cache::mergeTags($expected_tags, $page_cache_tags_referencing_entity);
    $this->verifyPageCache($listing_url, 'HIT', $expected_tags);

    // Prime the page cache for the empty listing.     $this->verifyPageCache($empty_entity_listing_url, 'MISS');
    // Verify a cache hit, but also the presence of the correct cache tags.     $this->verifyPageCache($empty_entity_listing_url, 'HIT', $empty_entity_listing_cache_tags);
    // Verify the entity type's list cache contexts are present.     $contexts_in_header = $this->getSession()->getResponseHeader('X-Drupal-Cache-Contexts');
    $this->assertEqualsCanonicalizing(Cache::mergeContexts($page_cache_contexts, $this->getAdditionalCacheContextsForEntityListing()), empty($contexts_in_header) ? [] : explode(' ', $contexts_in_header));

    // Prime the page cache for the listing containing the referenced entity.     $this->verifyPageCache($nonempty_entity_listing_url, 'MISS', $nonempty_entity_listing_cache_tags);
    // Verify a cache hit, but also the presence of the correct cache tags.     $this->verifyPageCache($nonempty_entity_listing_url, 'HIT', $nonempty_entity_listing_cache_tags);
    // Verify the entity type's list cache contexts are present.     $contexts_in_header = $this->getSession()->getResponseHeader('X-Drupal-Cache-Contexts');
    $this->assertEqualsCanonicalizing(Cache::mergeContexts($page_cache_contexts, $this->getAdditionalCacheContextsForEntityListing()), empty($contexts_in_header) ? [] : explode(' ', $contexts_in_header));

    // Verify that after modifying the referenced entity, there is a cache miss     // for every route except the one for the non-referencing entity.