Update identity-class.md

guides/v2.3/graphql/develop/identity-class.md

@@ -7,9 +7,11 @@ If you create a cacheable query (similar to those for product, category, and CMS
 
 An Identity class implements `Magento\Framework\GraphQl\Query\Resolver\IdentityInterface`. Your Identity class must contain the following elements:
 
-* A private string that specifies the path to the class that defines the module’s cache tag.
+* Choose a cache tag prefix for the entity.
 
-* Your implementation of the `getIdentities(array $resolvedData)` method. Generally, this method takes an array of query results and creates a new cache tag for each entity based on the original string and the unique identifier for each item to be cached. For example, the getIdentities method for the `CatalogGraphQl` component appends the product ID to the `cat_p` cache tag, such as `cat_p_1`, `cat_p_2`, and so on.
+* Your implementation of the `getIdentities(array $resolvedData)` method. The method maps the array of enties data to an array of cache tags, one for each entity.
+Generally, this method takes an array of query results and creates a cache tag for each entity based on the original string and the unique identifier for each item to be cached. For example, the getIdentities method for the `CatalogGraphQl` component appends the product ID to the `cat_p` cache tag prefix, such as `cat_p_1`, `cat_p_2`, and so on.  
+Usually the method also adds the cache tag without an appended ID to the result array, so all cache records can be removed at once, and not only cache records for specific entities.
 
 Use following example as the basis for your custom `Identity` class:
 
@@ -19,20 +21,20 @@ declare(strict_types=1);
 
 namespace PathToModule\Model\Resolver\MyModule;
 
-use Magento\Framework\GraphQl\Query\IdentityResolverInterface;
+use Magento\Framework\GraphQl\Query\Resolver\IdentityInterface;
 
 /**
  * Get identities from resolved data
  */
 class MyIdentity implements IdentityInterface
 {
-    private $cacheTag = \Path\To\Model\Class::CACHE_TAG;
+    private $cacheTag = \PathToModule\Model\MyEntity::CACHE_TAG;
 
     /**
      * Get identity tags from resolved data
      *
      * @param array $resolvedData
-     * @return int[]|string[]
+     * @return string[]
      */
     public function getIdentities(array $resolvedData): array
     {
@@ -42,7 +44,7 @@ class MyIdentity implements IdentityInterface
             $ids[] = sprintf('%s_%s', $this->cacheTag, $item['entity_id']);
         }
         if (!empty($ids)) {
-            array_unshift($ids, $this->cacheTag);
+            $ids[] = $this->cacheTag;
         }
         return $ids;
     }