diff --git a/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/Car.java b/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/Car.java
new file mode 100644
index 0000000000..a72d7dd0f1
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/Car.java
@@ -0,0 +1,98 @@
+package com.baeldung.methods;
+
+public class Car {
+
+    private final String make;
+    private final String model;
+    private final int year;
+    private final String color;
+    private final boolean automatic;
+    private final int numDoors;
+    private final String features;
+
+    private Car(CarBuilder carBuilder) {
+        this.make = carBuilder.make;
+        this.model = carBuilder.model;
+        this.year = carBuilder.year;
+        this.color = carBuilder.color;
+        this.automatic = carBuilder.automatic;
+        this.numDoors = carBuilder.numDoors;
+        this.features = carBuilder.features;
+    }
+
+    public String getMake() {
+        return make;
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public String getColor() {
+        return color;
+    }
+
+    public boolean isAutomatic() {
+        return automatic;
+    }
+
+    public int getNumDoors() {
+        return numDoors;
+    }
+
+    public String getFeatures() {
+        return features;
+    }
+
+    public static class CarBuilder {
+
+        private final String make;
+        private final String model;
+        private final int year;
+
+        private String color = "unknown";
+        private boolean automatic = false;
+        private int numDoors = 4;
+        private String features = "";
+
+        public CarBuilder(String make, String model, int year) {
+            this.make = make;
+            this.model = model;
+            this.year = year;
+        }
+
+        public CarBuilder color(String color) {
+            this.color = color;
+            return this;
+        }
+
+        public CarBuilder automatic(boolean automatic) {
+            this.automatic = automatic;
+            return this;
+        }
+
+        public CarBuilder numDoors(int numDoors) {
+            this.numDoors = numDoors;
+            return this;
+        }
+
+        public CarBuilder features(String features) {
+            this.features = features;
+            return this;
+        }
+
+        public Car build() {
+            return new Car(this);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "Car [make=" + make + ", model=" + model + ", year=" + year + ", color=" + color + ", automatic=" + automatic + ", numDoors=" + numDoors + ", features=" + features + "]";
+    }
+
+}
diff --git a/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/Motorcycle.java b/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/Motorcycle.java
new file mode 100644
index 0000000000..8a1fce4a5d
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/Motorcycle.java
@@ -0,0 +1,52 @@
+package com.baeldung.methods;
+
+import java.io.Serializable;
+
+public class Motorcycle extends Vehicle implements Serializable {
+
+    private static final long serialVersionUID = 5973661295933599929L;
+
+    private int year;
+    private String features = "";
+
+    public Motorcycle() {
+        super();
+    }
+
+    public Motorcycle(String make, String model, String color, int weight, boolean statusNew, int year) {
+        super(make, model, color, weight, statusNew);
+        this.year = year;
+    }
+
+    public Motorcycle(Vehicle vehicle, int year) {
+        super(vehicle);
+        this.year = year;
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public void setYear(int year) {
+        this.year = year;
+    }
+
+    public void setFeatures(String features) {
+        this.features = features;
+    }
+
+    public String getFeatures() {
+        return features;
+    }
+
+    public void addMotorcycleFeatures(String... features) {
+        StringBuilder str = new StringBuilder(this.getFeatures());
+        for (String feature : features) {
+            if (!str.toString().isEmpty())
+                str.append(", ");
+            str.append(feature);
+        }
+        this.setFeatures(str.toString());
+    }
+
+}
diff --git a/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/Vehicle.java b/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/Vehicle.java
new file mode 100644
index 0000000000..0c6964d255
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/Vehicle.java
@@ -0,0 +1,33 @@
+package com.baeldung.methods;
+
+public class Vehicle {
+
+    static String defaultValue = "DEFAULT";
+    private String make = defaultValue;
+    private String model = defaultValue;
+    private String color = defaultValue;
+    private int weight = 0;
+    private boolean statusNew = true;
+
+    public Vehicle() {
+        super();
+    }
+
+    public Vehicle(String make, String model, String color, int weight, boolean statusNew) {
+        this.make = make;
+        this.model = model;
+        this.color = color;
+        this.weight = weight;
+        this.statusNew = statusNew;
+    }
+
+    public Vehicle(Vehicle vehicle) {
+        this(vehicle.make, vehicle.model, vehicle.color, vehicle.weight, vehicle.statusNew);
+    }
+
+    @Override
+    public String toString() {
+        return "Vehicle [make=" + make + ", model=" + model + ", color=" + color + ", weight=" + weight + ", statusNew=" + statusNew + "]";
+    }
+
+}
diff --git a/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/VehicleProcessor.java b/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/VehicleProcessor.java
new file mode 100644
index 0000000000..a7d5975813
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop-methods/src/main/java/com/baeldung/methods/VehicleProcessor.java
@@ -0,0 +1,20 @@
+package com.baeldung.methods;
+
+public class VehicleProcessor {
+
+    Vehicle processVehicle(String make, String model, String color, int weight, boolean status) {
+        return new Vehicle(make, model, color, weight, status);
+    }
+
+    Vehicle processVehicle(Vehicle vehicle) {
+        return new Vehicle(vehicle);
+    }
+
+    Car processCar(Car car) {
+        return new Car.CarBuilder(car.getMake(), car.getModel(), car.getYear()).color(car.getColor())
+            .automatic(car.isAutomatic())
+            .features(car.getFeatures())
+            .build();
+    }
+
+}
\ No newline at end of file
diff --git a/core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/methods/VehicleProcessorUnitTest.java b/core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/methods/VehicleProcessorUnitTest.java
new file mode 100644
index 0000000000..928fbcb426
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop-methods/src/test/java/com/baeldung/methods/VehicleProcessorUnitTest.java
@@ -0,0 +1,58 @@
+package com.baeldung.methods;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class VehicleProcessorUnitTest {
+
+    VehicleProcessor vehicleProcessor = new VehicleProcessor();
+    Vehicle vehicle = new Vehicle("Ford", "Focus", "red", 2200, true);
+
+    @Test
+    void givenAllArguments_whenMethodCall_thenVerifyCallIsDoneCorrectly() {
+        Vehicle veh = vehicleProcessor.processVehicle("Ford", "Focus", "red", 2200, true);
+        assertThat(veh.toString()).hasToString(vehicle.toString());
+    }
+
+    @Test
+    void givenParameterObject_whenMethodCall_thenVerifyCallIsDoneCorrectly() {
+        Vehicle veh = vehicleProcessor.processVehicle(vehicle);
+        assertThat(veh.toString()).hasToString(vehicle.toString());
+    }
+
+    @Test
+    void givenJavaBeanPattern_whenMethodCall_thenVerifyCallIsDoneCorrectly() {
+        Motorcycle motorcycle = new Motorcycle("Ducati", "Monster", "yellow", 235, true, 2023);
+        motorcycle.setFeatures("GPS");
+
+        vehicleProcessor.processVehicle(motorcycle);
+        assertThat(motorcycle.getFeatures()).isEqualToIgnoringCase("GPS");
+    }
+
+    @Test
+    void givenJavaVarargs_whenMethodCall_thenAssertTheReturnedConcatenatedString() {
+        Motorcycle motorcycle = new Motorcycle("Ducati", "Monster", "red", 350, true, 2023);
+        motorcycle.addMotorcycleFeatures("abs");
+        assertThat(motorcycle.getFeatures()).isEqualToIgnoringCase("abs");
+
+        motorcycle.addMotorcycleFeatures("navi", "charger");
+        assertThat(motorcycle.getFeatures()).isEqualToIgnoringCase("abs, navi, charger");
+
+        motorcycle.addMotorcycleFeatures("wifi", "phone", "satellite");
+        assertThat(motorcycle.getFeatures()).isEqualToIgnoringCase("abs, navi, charger, wifi, phone, satellite");
+    }
+
+    @Test
+    void givenJavaBuilderPattern_whenMethodCall_thenVerifyCallIsDoneCorrectly() {
+        Car car = new Car.CarBuilder("Ford", "Focus", 2023).color("blue")
+            .automatic(true)
+            .features("abs, navi, charger, wifi, phone, satellite")
+            .build();
+
+        Car result = vehicleProcessor.processCar(car);
+
+        assertThat(result.toString()).hasToString(car.toString());
+    }
+
+}