@Test
 public void testWith() throws Exception {
   Iterable<StorageKey> partitions =
       new FileSystemPartitionIterator(
           fileSystem,
           testDirectory,
           strategy,
           schema,
           emptyConstraints.with("timestamp", oct_24_2013).toKeyPredicate());
   assertIterableEquals(keys.subList(16, 17), partitions);
 }