BAEL-1787 - using Lombok @Builder on methods (#4256)

* BAEL-1787 - using Lombok @Builder on methods

* BAEL-1787 - rename class. Add AssertJ to Lombok project.

* BAEL-1787 - rename class again. Change AssertJ tests.

lombok/src/main/java/com/baeldung/lombok/intro/ClientBuilder.java

@@ -0,0 +1,11 @@
+package com.baeldung.lombok.intro;
+
+import lombok.Builder;
+
+class ClientBuilder {
+
+    @Builder(builderMethodName = "builder")
+    public static ImmutableClient newClient(int id, String name) {
+        return new ImmutableClient(id, name);
+    }
+}

lombok/src/main/java/com/baeldung/lombok/intro/ImmutableClient.java

@@ -0,0 +1,11 @@
+package com.baeldung.lombok.intro;
+
+import lombok.Value;
+
+@Value
+final class ImmutableClient {
+
+    private int id;
+    private String name;
+
+}

lombok/src/test/java/com/baeldung/lombok/intro/BuilderMethodUnitTest.java

@@ -0,0 +1,18 @@
+package com.baeldung.lombok.intro;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.*;
+
+public class BuilderMethodUnitTest
+{
+
+    @Test
+    public void givenBuilderMethod_ClientIsBuilt() {
+        ImmutableClient testImmutableClient = ClientBuilder.builder().name("foo").id(1).build();
+        assertThat(testImmutableClient.getName())
+            .isEqualTo("foo");
+        assertThat(testImmutableClient.getId())
+            .isEqualTo(1);
+    }
+}