         DispatchQueue.main.async {
             var userInfo: [String: Any]? = nil
             if self.syncError != nil {
-                userInfo = [MirroredIndex.SyncErrorKey: self.syncError!]
+                userInfo = [MirroredIndex.syncErrorKey: self.syncError!]
             }
             NotificationCenter.default.post(name: MirroredIndex.SyncDidFinishNotification, object: self, userInfo: userInfo)
         }

            // Tag results as having a remote origin.
            var taggedContent: JSONObject? = content
            if taggedContent != nil {
                taggedContent?[MirroredIndex.JSONKeyOrigin] = MirroredIndex.JSONValueOriginRemote
            }
            completionHandler(taggedContent, error)
        })

                // Tag results as having a local origin.
                // NOTE: Each individual result is also automatically tagged, but having a top-level key allows for
                // more uniform processing.
                MirroredIndex.jsonKeyOrigin: MirroredIndex.jsonValueOriginLocal
            ]
        }
        assert(content != nil || error != nil)
