@Override
      protected Iterator<Integer> newTargetIterator() {
        return newDoubler(1, 2);
      }
    }.test();
  }

  public void testDoubler() {
    Iterable<Integer> doubled =
        new Iterable<Integer>() {
          @Override
          public Iterator<Integer> iterator() {
            return newDoubler(2, 32);
          }
        };

        long expected5 = 999999999999999999L;
        doc.put("key5", expected5);
        assertEquals(expected5, DocumentUtil.getValue(doc, "key5", Long.class).longValue());
    }

    public void test_double() {
        Map<String, Object> doc = new HashMap<>();

        double expected6 = 999.999;
        doc.put("key6", expected6);
        assertEquals(expected6, DocumentUtil.getValue(doc, "key6", Double.class));
    }