### Question:
Funnel { public List<T> run() { ArrayList<T> output = new ArrayList<>(Collections.nCopies(size, null)); for (Batch<?, T> batch : batches) { batch.convertInto(output); } return output; }  Batch<F, T> through(
      Function<? super List<F>, ? extends Collection<? extends T>> converter); void add(T element); List<T> run();  }### Answer:
@Test public void emptyFunnel() { assertThat(funnel.run()).isEmpty(); }