passed checklist and test

src/main/java/core/basesyntax/Car.java

@@ -1,17 +1,83 @@
 package core.basesyntax;
 
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 
-/**
- * Make this class immutable. See requirements in task description.
- */
-public class Car {
-    private int year;
-    private String color;
-    private List<Wheel> wheels;
-    private Engine engine;
+public final class Car {
+    private final int year;
+    private final String color;
+    private final List<Wheel> wheels;
+    private final Engine engine;
 
-    //implement this class
+    public Car(int year, String color, List<Wheel> wheels, Engine engine) {
+        this.year = year;
+        this.color = color;
+        this.wheels = getCopyWheels(wheels);
+        this.engine = engine == null ? null : engine.clone();
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public String getColor() {
+        return color;
+    }
+
+    public List<Wheel> getWheels() {
+        List<Wheel> copyWheels = new ArrayList<>();
+        for (Wheel wheel : this.wheels) {
+            copyWheels.add(wheel != null ? wheel.clone() : null);
+        }
+        return copyWheels;
+    }
+
+    public Engine getEngine() {
+        return engine == null ? null : engine.clone();
+    }
+
+    public Car changeEngine(Engine newEngine) {
+        return new Car(this.year, this.color, this.wheels, newEngine);
+    }
+
+    public Car changeColor(String newColor) {
+        return new Car(this.year, newColor, this.wheels, this.engine);
+    }
+
+    public Car addWheel(Wheel newWheel) {
+        List<Wheel> copyWheels = getCopyWheels(this.wheels);
+        copyWheels.add(newWheel.clone());
+        return new Car(this.year, this.color, copyWheels, this.engine);
+    }
+
+    private List<Wheel> getCopyWheels(List<Wheel> wheelsList) {
+        List<Wheel> copyWheels = new ArrayList<>();
+        for (Wheel wheel : wheelsList) {
+            copyWheels.add(wheel != null ? wheel.clone() : null);
+        }
+        return copyWheels;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        Car car = (Car) o;
+        return year == car.year
+                && Objects.equals(color, car.color)
+                && Objects.equals(wheels, car.wheels)
+                && Objects.equals(engine, car.engine);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(year, color, wheels, engine);
+    }
 
     @Override
     public String toString() {

src/main/java/core/basesyntax/Engine.java

@@ -1,10 +1,53 @@
 package core.basesyntax;
 
-public class Engine {
+import java.util.Objects;
+
+public class Engine implements Cloneable {
     private int horsePower;
     private String manufacturer;
 
-    //implement this class
+    public Engine(int horsePower, String manufacturer) {
+        this.horsePower = horsePower;
+        this.manufacturer = manufacturer;
+    }
+
+    public int getHorsePower() {
+        return horsePower;
+    }
+
+    public void setHorsePower(int horsePower) {
+        this.horsePower = horsePower;
+    }
+
+    public String getManufacturer() {
+        return manufacturer;
+    }
+
+    public void setManufacturer(String manufacturer) {
+        this.manufacturer = manufacturer;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        Engine engine = (Engine) obj;
+        return horsePower == engine.horsePower && Objects.equals(manufacturer, engine.manufacturer);
+    }
+
+    @Override
+    public Engine clone() {
+        return new Engine(this.horsePower, this.manufacturer);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(horsePower, manufacturer);
+    }
 
     @Override
     public String toString() {

src/main/java/core/basesyntax/Wheel.java

@@ -1,9 +1,43 @@
 package core.basesyntax;
 
-public class Wheel {
+import java.util.Objects;
+
+public class Wheel implements Cloneable {
     private int radius;
 
-    //implement this class
+    public Wheel(int radius) {
+        this.radius = radius;
+    }
+
+    public int getRadius() {
+        return radius;
+    }
+
+    public void setRadius(int radius) {
+        this.radius = radius;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(radius);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        Wheel wheel = (Wheel) obj;
+        return radius == wheel.radius;
+    }
+
+    @Override
+    public Wheel clone() {
+        return new Wheel(this.radius);
+    }
 
     @Override
     public String toString() {