@Test
public void testKeepLastMerger() {

    final Map<String, Integer> collected = Stream.of(
            toEntry("one", 1),
            toEntry("one", 2),
            toEntry("three", 3))
            .collect(entriesToMap(keepLastMerger()));
    assertEquals("value of 'one' should be 2", Integer.valueOf(2), collected.get("one"));
}