Merge pull request #8125 from eugenp/revert-8119-BAEL-3275-2

Revert "BAEL-3275: Using blocking queue for pub-sub"

immutables/src/test/java/com/baeldung/immutable/ImmutablePersonUnitTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.immutable;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mutabilitydetector.unittesting.MutabilityAssert.assertImmutable;
+
+public class ImmutablePersonUnitTest {
+
+    @Test
+    public void whenModifying_shouldCreateNewInstance() throws Exception {
+        final ImmutablePerson john = ImmutablePerson.builder()
+          .age(42)
+          .name("John")
+          .build();
+
+        final ImmutablePerson john43 = john.withAge(43);
+
+        assertThat(john)
+          .isNotSameAs(john43);
+
+        assertThat(john.getAge())
+          .isEqualTo(42);
+
+        assertImmutable(ImmutablePerson.class);
+    }
+}