@Test
 public void testPutMultipleKeys() throws Exception {
   List<String> keys =
       ImmutableList.of(
           "putMultipleKey1", "putMultipleKey2", "putMultipleKey3", "putMultipleKey4");
   Map<String, String> toAdd =
       ImmutableMap.of(
           "putMultipleKey1", "value1",
           "putMultipleKey2", "value2",
           "putMultipleKey3", "value3");
   Map<String, Optional<?>> expected =
       ImmutableMap.of(
           "putMultipleKey1", Optional.of("value1"),
           "putMultipleKey2", Optional.of("value2"),
           "putMultipleKey3", Optional.of("value3"),
           "putMultipleKey4", Optional.absent());
   LocalLookupConfig conf = new LocalLookupConfig();
   LocalStore localStore = new LocalStore(conf);
   localStore.putAll(toAdd);
   Map<String, Optional<String>> values = localStore.get(keys);
   localStore.close();
   assertEquals(keys.size(), values.size());
   assertEquals(expected.toString(), values.toString());
 }