             let deferreds: [Deferred<Void>] = available.map { filename in
                 let result = Deferred<Void>()
                 ContentBlockerHelper.ruleStore.removeContentRuleList(forIdentifier: filename) { _ in
-                   result.fill()
+                    result.fill(())
                 }
                 return result
             }

                        }
                        assert(rule != nil)

                        result.fill()
                    }
                }
            }

            let result = Deferred<Void>()
            ruleStore.lookUpContentRuleList(forIdentifier: filename) { contentRuleList, error in
                if contentRuleList != nil {
                    result.fill(())
                    return
                }
                loadJsonFromBundle(forResource: filename) { jsonString in
