adding alternative to remove nulls for list

Author: eugenp

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

@@ -4,6 +4,7 @@
 import static org.junit.Assert.assertThat;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 
@@ -29,6 +30,14 @@ public final void givenListContainsNulls_whenRemovingNullsWithPlainJava_thenCorr
         assertThat(list, hasSize(1));
     }
 
+    @Test
+    public final void givenListContainsNulls_whenRemovingNullsWithPlainJavaAlternative_thenCorrect() {
+        final List<Integer> list = Lists.newArrayList(null, 1, null);
+        list.removeAll(Collections.singleton(null));
+
+        assertThat(list, hasSize(1));
+    }
+
     @Test
     public final void givenListContainsNulls_whenRemovingNullsWithGuavaV1_thenCorrect() {
         final List<Integer> list = Lists.newArrayList(null, 1, null);