diff --git a/Sources/Bridge/Conceptual/Example.swift b/Sources/Bridge/Conceptual/Example.swift
index 46e7fed..e1bc91f 100644
--- a/Sources/Bridge/Conceptual/Example.swift
+++ b/Sources/Bridge/Conceptual/Example.swift
@@ -24,7 +24,7 @@
 import XCTest
 
 /// EN: The Abstraction defines the interface for the "control" part of the two
-/// class hierarchies. It maintains a reference to an object of the
+/// class hierarchies. It holds a reference to an object from the
 /// Implementation hierarchy and delegates all of the real work to this object.
 ///
 /// RU: Абстракция устанавливает интерфейс для «управляющей» части двух иерархий
diff --git a/Sources/ChainOfResponsibility/Conceptual/Example.swift b/Sources/ChainOfResponsibility/Conceptual/Example.swift
index e4d414b..90d6edd 100644
--- a/Sources/ChainOfResponsibility/Conceptual/Example.swift
+++ b/Sources/ChainOfResponsibility/Conceptual/Example.swift
@@ -17,7 +17,7 @@ import XCTest
 ///
 /// RU: Интерфейс Обработчика объявляет метод построения цепочки обработчиков.
 /// Он также объявляет метод для выполнения запроса.
-protocol Handler: class {
+protocol Handler: AnyObject {
 
     @discardableResult
     func setNext(handler: Handler) -> Handler
diff --git a/Sources/Command/RealWorld/Example.swift b/Sources/Command/RealWorld/Example.swift
index ba74b72..6f117a4 100644
--- a/Sources/Command/RealWorld/Example.swift
+++ b/Sources/Command/RealWorld/Example.swift
@@ -2,7 +2,7 @@ import Foundation
 import XCTest
 
 
-class DelayedOperation: Operation {
+class DelayedOperation: Operation, @unchecked Sendable {
 
     private var delay: TimeInterval
 
@@ -58,7 +58,7 @@ class DelayedOperation: Operation {
     }
 }
 
-class WindowOperation: DelayedOperation {
+class WindowOperation: DelayedOperation, @unchecked Sendable {
 
     override func main() {
         print("\(self): Windows are closed via HomeKit.")
@@ -67,7 +67,7 @@ class WindowOperation: DelayedOperation {
     override var description: String { return "WindowOperation" }
 }
 
-class DoorOperation: DelayedOperation {
+class DoorOperation: DelayedOperation, @unchecked Sendable {
 
     override func main() {
         print("\(self): Doors are closed via HomeKit.")
@@ -76,7 +76,7 @@ class DoorOperation: DelayedOperation {
     override var description: String { return "DoorOperation" }
 }
 
-class TaxiOperation: DelayedOperation {
+class TaxiOperation: DelayedOperation, @unchecked Sendable {
 
     override func main() {
         print("\(self): Taxi is ordered via Uber")
diff --git a/Sources/Facade/Conceptual/Example.swift b/Sources/Facade/Conceptual/Example.swift
index b0b0e75..cbd1233 100644
--- a/Sources/Facade/Conceptual/Example.swift
+++ b/Sources/Facade/Conceptual/Example.swift
@@ -66,13 +66,13 @@ class Facade {
 class Subsystem1 {
 
     func operation1() -> String {
-        return "Sybsystem1: Ready!\n"
+        return "Subsystem1: Ready!\n"
     }
 
     // ...
 
     func operationN() -> String {
-        return "Sybsystem1: Go!\n"
+        return "Subsystem1: Go!\n"
     }
 }
 
@@ -82,13 +82,13 @@ class Subsystem1 {
 class Subsystem2 {
 
     func operation1() -> String {
-        return "Sybsystem2: Get ready!\n"
+        return "Subsystem2: Get ready!\n"
     }
 
     // ...
 
     func operationZ() -> String {
-        return "Sybsystem2: Fire!\n"
+        return "Subsystem2: Fire!\n"
     }
 }
 
diff --git a/Sources/Facade/RealWorld/Example.swift b/Sources/Facade/RealWorld/Example.swift
index b51ea1e..c8beca4 100644
--- a/Sources/Facade/RealWorld/Example.swift
+++ b/Sources/Facade/RealWorld/Example.swift
@@ -10,7 +10,7 @@ class FacadeRealWorld: XCTestCase {
     /// In the real project, you probably will use third-party libraries. For
     /// instance, to download images.
     ///
-    /// Therefore, facade and wrapping it is a good way to use a third party API
+    /// Therefore, facade and wrapping it is a good way to use a third-party API
     /// in the client code. Even if it is your own library that is connected to
     /// a project.
     ///
@@ -24,7 +24,7 @@ class FacadeRealWorld: XCTestCase {
     /// fits most client needs. Moreover, it can set frequently used or default
     /// parameters.
 
-    func testFacedeRealWorld() {
+    func testFacadeRealWorld() {
 
         let imageView = UIImageView()
 
@@ -46,7 +46,7 @@ class FacadeRealWorld: XCTestCase {
 
 private extension UIImageView {
 
-    /// This extension plays a facede role.
+    /// This extension plays a facade role.
 
     func downloadImage(at url: URL?) {
 
@@ -68,7 +68,7 @@ private extension UIImageView {
 
 private class ImageDownloader {
 
-    /// Third party library or your own solution (subsystem)
+    /// Third-party library or your own solution (subsystem)
 
     typealias Completion = (UIImage, Error?) -> ()
     typealias Progress = (Int, Int) -> ()
diff --git a/Sources/FactoryMethod/RealWorld/Example.swift b/Sources/FactoryMethod/RealWorld/Example.swift
index b396380..a8aee55 100644
--- a/Sources/FactoryMethod/RealWorld/Example.swift
+++ b/Sources/FactoryMethod/RealWorld/Example.swift
@@ -111,7 +111,7 @@ private class ClientCode {
 
     func present(info: String, with factory: ProjectorFactory) {
 
-        /// Check wheater a client code already present smth...
+        /// Check whether the client code is already presenting something...
 
         guard let projector = currentProjector else {
 
diff --git a/Sources/Flyweight/Conceptual/Example.swift b/Sources/Flyweight/Conceptual/Example.swift
index fa85200..d21ee7c 100644
--- a/Sources/Flyweight/Conceptual/Example.swift
+++ b/Sources/Flyweight/Conceptual/Example.swift
@@ -30,7 +30,7 @@ class Flyweight {
     }
 
     func operation(uniqueState: [String]) {
-        print("Flyweight: Displaying shared (\(sharedState)) and unique (\(uniqueState) state.\n")
+        print("Flyweight: Displaying shared (\(sharedState)) and unique (\(uniqueState)) state.\n")
     }
 }
 
diff --git a/Sources/Flyweight/RealWorld/Example.swift b/Sources/Flyweight/RealWorld/Example.swift
index 15639c1..34c7fc8 100644
--- a/Sources/Flyweight/RealWorld/Example.swift
+++ b/Sources/Flyweight/RealWorld/Example.swift
@@ -27,7 +27,7 @@ class FlyweightRealWorld: XCTestCase {
 
         /// Displaying objects for the 2-nd time.
         ///
-        /// Note: Cached object of the appearance will be reused this time.
+        /// Note: The cached appearance object will be reused this time.
 
         print("\nClient: I have a new dog, let's show it the same way!\n")
 
@@ -93,7 +93,7 @@ struct Animal: Equatable {
 
 struct Appearance: Equatable {
 
-    /// This object contains a predefined appearance of every cell
+    /// This object contains the predefined appearance for each cell.
 
     let photos: [UIImage]
     let backgroundColor: UIColor
diff --git a/Sources/Iterator/Conceptual/Example.swift b/Sources/Iterator/Conceptual/Example.swift
index 7396f03..4559a5b 100644
--- a/Sources/Iterator/Conceptual/Example.swift
+++ b/Sources/Iterator/Conceptual/Example.swift
@@ -11,7 +11,7 @@
 /// - The `AnyIterator<Element>` struct provides basic iterator implementation:
 /// https://developer.apple.com/documentation/swift/anyiterator
 ///
-/// In this examples we'll see how to use both of these mechanisms.
+/// In this example, we'll see how to use both of these mechanisms.
 ///
 /// RU: Паттерн Итератор
 ///
@@ -32,7 +32,7 @@
 import XCTest
 
 /// EN: This is a collection that we're going to iterate through using an
-/// iterator derived from IteratorProtocol.
+/// iterator that conforms to IteratorProtocol.
 ///
 /// RU: Это коллекция, которую мы будем перебирать используя итератор,
 /// реализующий IteratorProtocol.
diff --git a/Sources/Iterator/RealWorld/Example.swift b/Sources/Iterator/RealWorld/Example.swift
index b84a314..81c49c1 100644
--- a/Sources/Iterator/RealWorld/Example.swift
+++ b/Sources/Iterator/RealWorld/Example.swift
@@ -68,13 +68,13 @@ class Tree<T> {
 
     private func preOrder(_ body: Block) {
         body(value)
-        left?.inOrder(body)
-        right?.inOrder(body)
+        left?.preOrder(body)
+        right?.preOrder(body)
     }
 
     private func postOrder(_ body: Block) {
-        left?.inOrder(body)
-        right?.inOrder(body)
+        left?.postOrder(body)
+        right?.postOrder(body)
         body(value)
     }
 }
diff --git a/Sources/Observer/Conceptual/Example.swift b/Sources/Observer/Conceptual/Example.swift
index 9af4ef2..67a0483 100644
--- a/Sources/Observer/Conceptual/Example.swift
+++ b/Sources/Observer/Conceptual/Example.swift
@@ -116,7 +116,7 @@ class Subject {
 ///
 /// RU: Наблюдатель объявляет метод уведомления, который используют издатели для
 /// оповещения.
-protocol Observer: class {
+protocol Observer: AnyObject {
 
     func update(subject: Subject)
 }
diff --git a/Sources/Singleton/RealWorld/Example.swift b/Sources/Singleton/RealWorld/Example.swift
index 6cd87ec..867051a 100644
--- a/Sources/Singleton/RealWorld/Example.swift
+++ b/Sources/Singleton/RealWorld/Example.swift
@@ -38,11 +38,11 @@ class SingletonRealWorld: XCTestCase {
 class BaseVC: UIViewController, MessageSubscriber {
 
     func accept(new messages: [Message]) {
-        /// handle new messages in the base class
+        /// Handles new messages in the base class
     }
 
     func accept(removed messages: [Message]) {
-        /// handle removed messages in the base class
+        /// Hanldes removed messages in the base class
     }
 
     func startReceiveMessages() {
@@ -60,12 +60,12 @@ class MessagesListVC: BaseVC {
 
     override func accept(new messages: [Message]) {
         print("MessagesListVC accepted 'new messages'")
-        /// handle new messages in the child class
+        /// Handles new messages in the child class
     }
 
     override func accept(removed messages: [Message]) {
         print("MessagesListVC accepted 'removed messages'")
-        /// handle removed messages in the child class
+        /// Handles removed messages in the child class
     }
 
     override func startReceiveMessages() {
@@ -78,12 +78,12 @@ class ChatVC: BaseVC {
 
     override func accept(new messages: [Message]) {
         print("ChatVC accepted 'new messages'")
-        /// handle new messages in the child class
+        /// Handles new messages in the child class
     }
 
     override func accept(removed messages: [Message]) {
         print("ChatVC accepted 'removed messages'")
-        /// handle removed messages in the child class
+        /// Handles removed messages in the child class
     }
 
     override func startReceiveMessages() {
diff --git a/Sources/State/Conceptual/Example.swift b/Sources/State/Conceptual/Example.swift
index 1822f57..09b6fd2 100644
--- a/Sources/State/Conceptual/Example.swift
+++ b/Sources/State/Conceptual/Example.swift
@@ -61,7 +61,7 @@ class Context {
 /// Конкретные Состояния, а также предоставляет обратную ссылку на объект
 /// Контекст, связанный с Состоянием. Эта обратная ссылка может использоваться
 /// Состояниями для передачи Контекста другому Состоянию.
-protocol State: class {
+protocol State: AnyObject {
 
     func update(context: Context)