doc.put("key", listWithNulls);

        String[] result = DocumentUtil.getValue(doc, "key", String[].class);
        assertArrayEquals(new String[] { "a", "b", "c" }, result);
    }

    public void test_empty_list() {
        Map<String, Object> doc = new HashMap<>();
        doc.put("key", new ArrayList<>());

        assertNull(DocumentUtil.getValue(doc, "key", String.class));

    assertSame(set, set.subSet("c", "f"));
  }

  public void testEmpty_first() {
    SortedSet<String> set = of();
    assertThrows(NoSuchElementException.class, () -> set.first());
  }

  public void testEmpty_last() {
    SortedSet<String> set = of();
    assertThrows(NoSuchElementException.class, () -> set.last());
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester