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 {

    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");

    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() {

    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);
  }

  }

  @GwtIncompatible // unreasonably slow
  public void testKeySetIteration() {
    new IteratorTester<String>(
        6,
        MODIFIABLE,
        newLinkedHashSet(asList("foo", "bar", "baz", "dog", "cat")),
        IteratorTester.KnownOrder.KNOWN_ORDER) {
      private @Nullable Multimap<String, Integer> multimap;

      @Override
      protected Iterator<String> newTargetIterator() {

  protected Map<String, Map<Integer, Character>> makePopulatedMap() {
    Table<Integer, String, String> table = HashBasedTable.create();
    table.put(1, "foo", "apple");
    table.put(1, "bar", "banana");
    table.put(3, "foo", "cat");
    return Tables.transformValues(table, FIRST_CHARACTER).columnMap();
  }

            + "(bar,1)=b, (bar,2)=null, (bar,3)=null, "
            + "(cat,1)=null, (cat,2)=null, (cat,3)=null]",
        table.cellSet().toString());
  }

  public void testRowKeySetToString_ordered() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals("[foo, bar, cat]", table.rowKeySet().toString());
  }

  public void testColumnKeySetToString_ordered() {

            + "(bar,1)=b, (bar,2)=null, (bar,3)=null, "
            + "(cat,1)=null, (cat,2)=null, (cat,3)=null]",
        table.cellSet().toString());
  }

  public void testRowKeySetToString_ordered() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals("[foo, bar, cat]", table.rowKeySet().toString());
  }

  public void testColumnKeySetToString_ordered() {