guava examples for ordering

guava/src/test/java/org/baeldung/guava/collections/GuavaOrderingExamplesTest.java

@@ -1,5 +1,6 @@
 package org.baeldung.guava.collections;
 
+import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.nullValue;
 import static org.junit.Assert.assertThat;
 
@@ -10,6 +11,7 @@ import java.util.List;
 import org.junit.Test;
 
 import com.google.common.collect.Ordering;
+import com.google.common.primitives.Ints;
 
 public class GuavaOrderingExamplesTest {
 
@@ -35,4 +37,20 @@ public class GuavaOrderingExamplesTest {
         Collections.sort(nums, Ordering.natural().nullsLast().reverse());
         assertThat(nums.get(0), nullValue());
     }
+
+    @Test
+    public final void whenSortingCollectionsOfStringsByLenght_thenCorrectlySorted() {
+        final List<String> toSort = Arrays.asList("aa", "b", null, "ccc");
+        final Ordering<String> byLength = new Ordering<String>() {
+            @Override
+            public int compare(final String s1, final String s2) {
+                return Ints.compare(s1.length(), s2.length());
+            }
+        };
+
+        Collections.sort(toSort, byLength.nullsFirst());
+        assertThat(toSort.get(0), nullValue());
+        assertThat(toSort.get(1), equalTo("b"));
+    }
+
 }