code: @Test public void should_fail_if_actual_does_not_contains_every_expected_entries() throws Exception {
    AssertionInfo info=someInfo();
    String[] expectedKeys={"name","color"};
    Map<String,String> underTest=(Map<String,String>)Maps.mapOf(entry("name","Yoda"));
    try {
      maps.assertContainsOnlyKeys(info,underTest,expectedKeys);
    }
   catch (  AssertionError e) {
      verify(failures).failure(info,shouldContainOnlyKeys(underTest,expectedKeys,newHashSet("color"),emptySet()));
      return;
    }
    shouldHaveThrown(AssertionError.class);
  }
  