@Test
public void testUpdateMulipleEntries_shouldWork() throws Exception {

    Map<String, String> original = ImmutableMap.of("foo", "bar", "test", "42", "other", "bleh");
    Map<String, String> oldMap = ImmutableMap.of("foo", "bar", "test", "42");
    Map<String, String> newMap = ImmutableMap.of("foo", "bar2", "test", "41", "x", "y");
    MapDifference<String, String> difference = Maps.difference(oldMap, newMap);
    Map<String, String> result = ConfigUtils.updateMap(original, difference);
    assertThat(result,
        is((Map<String, String>) ImmutableMap.of("foo", "bar2", "test", "41", "x", "y", "other", "bleh")));
}