http_cache_forever in learning objects index

app/controllers/v1/learning_objects_controller.rb

@@ -15,7 +15,9 @@ class V1::LearningObjectsController < ApplicationController
   def index
     learning_objects = paginate LearningObject.includes(:tags, :publisher, :language, :license, :subjects, :educational_stages, :reviews)
     serializer = params[:obaa].nil? ? LearningObjectSerializer : LearningObjectObaaSerializer
-    render json: learning_objects, each_serializer: serializer
+    http_cache_forever do
+      render json: learning_objects, each_serializer: serializer
+    end
   end
 
   # GET /learning_objects/1