unfiltered.put("apple", 2);
    unfiltered.put("banana", 6);
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 5);

    SortedMap<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);
    assertEquals("banana", filtered.firstKey());
    assertEquals("cat", filtered.lastKey());
  }

  public void testHeadSubTailMap_FilteredMap() {

    Map<String, Integer> unfiltered = createUnfiltered();
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 2);
    unfiltered.put("horse", 5);
    Map<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);
    assertEquals(ImmutableMap.of("cat", 3, "horse", 5), filtered);

    filtered.put("chicken", 7);
    assertEquals(ImmutableMap.of("cat", 3, "horse", 5, "chicken", 7), filtered);

    try {

    Map<String, Integer> unfiltered = createUnfiltered();
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 2);
    unfiltered.put("horse", 5);
    Map<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);
    assertEquals(ImmutableMap.of("cat", 3, "horse", 5), filtered);

    filtered.put("chicken", 7);
    assertEquals(ImmutableMap.of("cat", 3, "horse", 5, "chicken", 7), filtered);

    try {

    unfiltered.put("apple", 2);
    unfiltered.put("banana", 6);
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 5);

    SortedMap<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);
    assertEquals("banana", filtered.firstKey());
    assertEquals("cat", filtered.lastKey());
  }

  public void testHeadSubTailMap_FilteredMap() {

    } catch (NullPointerException expected) {
    }
    try {
      table.put("cat", null, cellValue('d'));
      fail();
    } catch (NullPointerException expected) {
    }
    if (supportsNullValues()) {
      assertNull(table.put("cat", 2, null));
      assertTrue(table.contains("cat", 2));
    } else {
      try {
        table.put("cat", 2, null);
        fail();
      } catch (NullPointerException expected) {
      }

    table.put("foo", 4, 'a');
    table.put("cat", 1, 'b');
    table.clear();
    populate(table, data);
    return table;
  }

  @Override
  protected TreeBasedTable<String, Integer, Character> create(@Nullable Object... data) {
    TreeBasedTable<String, Integer, Character> table = TreeBasedTable.create();
    table.put("foo", 4, 'a');
    table.put("cat", 1, 'b');
    table.clear();
    populate(table, data);

    assertThat(m.keySet()).containsExactly("boy", "girl", "cat", "dog").inOrder();
    assertThat(m)
        .isEqualTo(ImmutableMap.of("boy", "tom", "girl", "tina", "cat", "kitty", "dog", "tommy"));

    // try in a different order
    m = COMMA_SPLITTER.withKeyValueSeparator(":").split("girl:tina,boy:tom,dog:tommy,cat:kitty");

  public void testCopyOfSparse() {
    Table<Character, Integer, String> table = TreeBasedTable.create();
    table.put('x', 2, "foo");
    table.put('r', 1, "bar");
    table.put('c', 3, "baz");
    table.put('b', 7, "cat");
    table.put('e', 5, "dog");
    table.put('c', 0, "axe");
    table.put('e', 3, "tub");
    table.put('r', 4, "foo");
    table.put('x', 5, "bar");
    validateTableCopies(table);
  }

    assertThat(m.keySet()).containsExactly("boy", "girl", "cat", "dog").inOrder();
    assertThat(m)
        .isEqualTo(ImmutableMap.of("boy", "tom", "girl", "tina", "cat", "kitty", "dog", "tommy"));

    // try in a different order
    m = COMMA_SPLITTER.withKeyValueSeparator(":").split("girl:tina,boy:tom,dog:tommy,cat:kitty");

    protected void writeFesenCat(final ZipOutputStream zos, final String id) {
        Arrays.stream(CAT_NAMES).forEach(name -> {
            final ZipEntry entry = new ZipEntry(id + "/es_cat_" + name + ".txt");
            try {
                zos.putNextEntry(entry);
                try (CurlResponse response = ComponentUtil.getCurlHelper().get("/_cat/" + name).param("v", "").execute()) {