Summarize internal UserDefaults observation class

Sources/Defaults/Defaults+iCloud.swift

@@ -249,7 +249,7 @@ final class iCloudSynchronizer {
 	@Atomic(value: []) private var remoteSyncingKeys: Set<Defaults.Keys>
 
 	// TODO: Replace it with async stream when Swift supports custom executors.
-	private lazy var localKeysMonitor: Defaults.CompositeUserDefaultsAnyKeyObservation = .init { [weak self] observable in
+	private lazy var localKeysMonitor: Defaults.UserDefaultsAnyKeysObservation = .init { [weak self] (observable, _) in
 		guard
 			let self,
 			let suite = observable.suite,

Sources/Defaults/Defaults.swift

@@ -239,7 +239,7 @@ extension Defaults {
 		initial: Bool = true
 	) -> AsyncStream<Value> { // TODO: Make this `some AsyncSequence<Value>` when Swift 6 is out.
 		.init { continuation in
-			let observation = UserDefaultsKeyObservation2(object: key.suite, key: key.name) { change in
+			let observation = UserDefaultsAnyKeysObservation(object: key.suite, key: key.name) { (_, change) in
 				// TODO: Use the `.deserialize` method directly.
 				let value = KeyChange(change: change, defaultValue: key.defaultValue).newValue
 				continuation.yield(value)
@@ -275,7 +275,7 @@ extension Defaults {
 	) -> AsyncStream<Void> { // TODO: Make this `some AsyncSequence<Value>` when Swift 6 is out.
 		.init { continuation in
 			let observations = keys.indexed().map { index, key in
-				let observation = UserDefaultsKeyObservation2(object: key.suite, key: key.name) { _ in
+				let observation = UserDefaultsAnyKeysObservation(object: key.suite, key: key.name) { (_, _) in
 					continuation.yield()
 				}
 

Sources/Defaults/Observation+Combine.swift

@@ -7,16 +7,16 @@ extension Defaults {
 	*/
 	final class DefaultsSubscription<SubscriberType: Subscriber>: Subscription where SubscriberType.Input == BaseChange {
 		private var subscriber: SubscriberType?
-		private var observation: UserDefaultsKeyObservation?
+		private var observation: UserDefaultsAnyKeysObservation?
 		private let options: ObservationOptions
 
 		init(subscriber: SubscriberType, suite: UserDefaults, key: String, options: ObservationOptions) {
 			self.subscriber = subscriber
 			self.options = options
-			self.observation = UserDefaultsKeyObservation(
+			self.observation = UserDefaultsAnyKeysObservation(
 				object: suite,
 				key: key,
-				callback: observationCallback(_:)
+				observationCallback
 			)
 		}
 
@@ -33,7 +33,7 @@ extension Defaults {
 			observation?.start(options: options)
 		}
 
-		private func observationCallback(_ change: BaseChange) {
+		private func observationCallback(_: SuiteKeyPair, change: BaseChange) {
 			_ = subscriber?.receive(change)
 		}
 	}