}

  public void testRemove() {
    TestMap map = new TestMap();
    map.put("foo", 1);
    assertFalse(map.remove("foo", 2));
    assertFalse(map.remove("bar", 1));
    assertEquals(Integer.valueOf(1), map.get("foo"));
    assertTrue(map.remove("foo", 1));
    assertTrue(map.isEmpty());
  }

  public void testReplace() {
    TestMap map = new TestMap();
    map.put("foo", 1);

    } catch (IllegalArgumentException expected) {
    }
  }

  public void testGap_connectedAdjacentYieldsEmpty() {
    Range<Integer> range = Range.open(3, 4);

    assertEquals(Range.closedOpen(4, 4), range.gap(Range.atLeast(4)));
    assertEquals(Range.openClosed(3, 3), range.gap(Range.atMost(3)));
  }

  public void testGap_general() {
    Range<Integer> openRange = Range.open(4, 8);

    Joiner j = Joiner.on("x").useForNull("y");
    try {
      j = j.useForNull("y");
      fail();
    } catch (UnsupportedOperationException expected) {
    }
  }

  public void testMap() {
    MapJoiner j = Joiner.on(';').withKeyValueSeparator(':');
    assertEquals("", j.join(ImmutableMap.of()));
    assertEquals(":", j.join(ImmutableMap.of("", "")));

      return super.setValue(value);
    }

    private static final long serialVersionUID = 0;
  }

  static class TestMap<K, V> extends SynchronizedMapTest.TestMap<K, V>
      implements NavigableMap<K, V> {

    public TestMap(NavigableMap<K, V> delegate, Object mutex) {
      super(delegate, mutex);
    }

    @Override
    protected NavigableMap<K, V> delegate() {

  protected <K, V> Map<K, V> create() {
    TestMap<K, V> inner = new TestMap<>(new HashMap<K, V>(), mutex);
    Map<K, V> outer = Synchronized.map(inner, mutex);
    return outer;
  }

  static class TestMap<K, V> extends ForwardingMap<K, V> implements Serializable {
    public final Object mutex;
    private Map<K, V> delegate;

    public TestMap(Map<K, V> delegate, Object mutex) {
      checkNotNull(mutex);

  }

  public void testMap_noSuchFile() throws IOException {
    // Setup
    File file = createTempFile();
    boolean deleted = file.delete();
    assertTrue(deleted);

    // Test
    assertThrows(FileNotFoundException.class, () -> Files.map(file));
  }

  public void testMap_readWrite() throws IOException {
    // Test data
    int size = 1024;

      return super.setValue(value);
    }

    private static final long serialVersionUID = 0;
  }

  static class TestMap<K, V> extends SynchronizedMapTest.TestMap<K, V>
      implements NavigableMap<K, V> {

    public TestMap(NavigableMap<K, V> delegate, Object mutex) {
      super(delegate, mutex);
    }

    @Override
    protected NavigableMap<K, V> delegate() {

    // Test compat address.
    testIp = (Inet6Address) InetAddresses.forString("::1.2.3.4");
    assertTrue(InetAddresses.hasEmbeddedIPv4ClientAddress(testIp));
    InetAddress ipv4 = InetAddresses.forString("1.2.3.4");
    assertEquals(ipv4, InetAddresses.getEmbeddedIPv4ClientAddress(testIp));

    // Test 6to4 address.
    testIp = (Inet6Address) InetAddresses.forString("2002:0102:0304::1");

  }

  public void testMap_noSuchFile() throws IOException {
    // Setup
    File file = createTempFile();
    boolean deleted = file.delete();
    assertTrue(deleted);

    // Test
    assertThrows(FileNotFoundException.class, () -> Files.map(file));
  }

  public void testMap_readWrite() throws IOException {
    // Test data
    int size = 1024;

    } catch (IllegalArgumentException expected) {
    }
  }

  public void testGap_connectedAdjacentYieldsEmpty() {
    Range<Integer> range = Range.open(3, 4);

    assertEquals(Range.closedOpen(4, 4), range.gap(Range.atLeast(4)));
    assertEquals(Range.openClosed(3, 3), range.gap(Range.atMost(3)));
  }

  public void testGap_general() {
    Range<Integer> openRange = Range.open(4, 8);