/resources/user_list.proto

--- v14/resources/user_list.proto   2023-10-18 04:25:31.000000000 +0000
+++ v15/resources/user_list.proto   2023-10-18 04:25:35.000000000 +0000
@@ -182,9 +182,13 @@
         21;

     // User list that is a custom combination of user lists and user interests.
-    google.ads.googleads.v14.common.LogicalUserListInfo logical_user_list = 22;
+    google.ads.googleads.v15.common.LogicalUserListInfo logical_user_list = 22;

     // User list targeting as a collection of conversion or remarketing actions.
-    google.ads.googleads.v14.common.BasicUserListInfo basic_user_list = 23;
+    google.ads.googleads.v15.common.BasicUserListInfo basic_user_list = 23;
+
+    // Immutable. Lookalike User List.
+    google.ads.googleads.v15.common.LookalikeUserListInfo lookalike_user_list =
+        36 [(google.api.field_behavior) = IMMUTABLE];
   }
 }