### Question:
BatchChain implements Iterable<Batch> { public boolean isEmpty() { return batches.isEmpty(); }  NavigableSet<Batch> batchesBeforeInclusive(final Batch batch); NavigableSet<Batch> batchesBeforeExclusive(final Batch batch); void add(final Batch batch); NavigableSet<Batch> batchesAfterInclusive(final Batch batch); NavigableSet<Batch> batchesAfterExclusive(final Batch batch); NavigableSet<Batch> batchesBetweenInclusive(final Batch from, final Batch to); NavigableSet<Batch> batchesBetweenExclusive(final Batch from, final Batch to); Optional<Batch> previousNonEmptyBatch(final Batch batch); Optional<Batch> nextNonEmptyBatch(final Batch batch); Optional<Batch> firstImportableBatch(); void removeUpToIncluding(final Batch batch); void removeAll(); Optional<Batch> last(); boolean contains(final Batch batch); boolean isEmpty(); @Override Iterator<Batch> iterator(); @Override void forEach(final Consumer<? super Batch> action); @Override Spliterator<Batch> spliterator(); Stream<Batch> stream();  }### Answer:
@Test void isEmpty_shouldBeTrueWhenChainIsEmpty() { assertThat(batchChain.isEmpty()).isTrue(); }