Merge commit '7621e2f8dec938cf48181c8b10afc9b01f444e68' into beta

submodules/TelegramCore/Sources/TelegramEngine/Preferences/TelegramEnginePreferences.swift

@@ -0,0 +1,22 @@
+import Foundation
+import SwiftSignalKit
+import Postbox
+
+public extension TelegramEngine {
+    final class Preferences {
+        private let account: Account
+
+        init(account: Account) {
+            self.account = account
+        }
+
+        public func update(id: ValueBoxKey, _ f: @escaping (PreferencesEntry?) -> PreferencesEntry?) -> Signal<Never, NoError> {
+            return self.account.postbox.transaction { transaction -> Void in
+                transaction.updatePreferencesEntry(key: id, { entry in
+                    return f(entry)
+                })
+            }
+            |> ignoreValues
+        }
+    }
+}