minor cleanup

Author: eugenp

core-java/src/test/java/org/baeldung/java/collections/JavaCollectionCleanupUnitTest.java

@@ -3,6 +3,8 @@
 import static org.hamcrest.Matchers.hasSize;
 import static org.junit.Assert.assertThat;
 
+import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 
 import org.apache.commons.collections4.CollectionUtils;
@@ -12,10 +14,11 @@
 import com.google.common.base.Predicates;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
 
 public class JavaCollectionCleanupUnitTest {
 
-    // removing nulls
+    // tests - removing nulls
 
     @Test
     public final void givenListContainsNulls_whenRemovingNullsWithPlainJava_thenCorrect() {
@@ -50,4 +53,22 @@ public final void givenListContainsNulls_whenRemovingNullsWithCommonsCollections
         assertThat(list, hasSize(3));
     }
 
+    // tests - remove duplicates
+
+    @Test
+    public final void givenListContainsDuplicates_whenRemovingDuplicatesWithPlainJava_thenCorrect() {
+        final List<Integer> listWithDuplicates = Lists.newArrayList(0, 1, 2, 3, 0, 0);
+        final List<Integer> listWithoutDuplicates = new ArrayList<>(new HashSet<>(listWithDuplicates));
+
+        assertThat(listWithoutDuplicates, hasSize(4));
+    }
+
+    @Test
+    public final void givenListContainsDuplicates_whenRemovingDuplicatesWithGuava_thenCorrect() {
+        final List<Integer> listWithDuplicates = Lists.newArrayList(0, 1, 2, 3, 0, 0);
+        final List<Integer> listWithoutDuplicates = Lists.newArrayList(Sets.newHashSet(listWithDuplicates));
+
+        assertThat(listWithoutDuplicates, hasSize(4));
+    }
+
 }