Issue #2354705 by yannisc: Mark a couple of asset services as non public

core/core.services.yml

@@ -1036,10 +1036,13 @@ services:
     arguments: [ '@asset.css.collection_grouper', '@asset.css.optimizer', '@asset.css.dumper', '@state' ]
   asset.css.optimizer:
     class: Drupal\Core\Asset\CssOptimizer
+    public: false
   asset.css.collection_grouper:
     class: Drupal\Core\Asset\CssCollectionGrouper
+    public: false
   asset.css.dumper:
     class: Drupal\Core\Asset\AssetDumper
+    public: false
   asset.js.collection_renderer:
     class: Drupal\Core\Asset\JsCollectionRenderer
     arguments: [ '@state' ]
@@ -1048,21 +1051,26 @@ services:
     arguments: [ '@asset.js.collection_grouper', '@asset.js.optimizer', '@asset.js.dumper', '@state' ]
   asset.js.optimizer:
     class: Drupal\Core\Asset\JsOptimizer
+    public: false
   asset.js.collection_grouper:
     class: Drupal\Core\Asset\JsCollectionGrouper
+    public: false
   asset.js.dumper:
     class: Drupal\Core\Asset\AssetDumper
+    public: false
   library.discovery:
     class: Drupal\Core\Asset\LibraryDiscovery
     arguments: ['@library.discovery.collector', '@module_handler']
   library.discovery.collector:
     class: Drupal\Core\Asset\LibraryDiscoveryCollector
     arguments: ['@cache.discovery', '@lock', '@library.discovery.parser']
+    public: false
     tags:
       - { name: needs_destruction }
   library.discovery.parser:
     class: Drupal\Core\Asset\LibraryDiscoveryParser
     arguments: ['@app.root', '@module_handler']
+    public: false
   info_parser:
     class: Drupal\Core\Extension\InfoParser
   twig: