Array.wrap is an overhead as there is already check for class

activerecord/lib/active_record/nested_attributes.rb

@@ -382,7 +382,7 @@ def assign_nested_attributes_for_collection_association(association_name, attrib
       if attributes_collection.is_a? Hash
         keys = attributes_collection.keys
         attributes_collection = if keys.include?('id') || keys.include?(:id)
-          Array.wrap(attributes_collection)
+          [attributes_collection]
         else
           attributes_collection.values
         end