return keySet;
  }

  @Override
  public ImmutableSortedSet<K> descendingKeySet() {
    return keySet.descendingSet();
  }

  /**
   * Serialized type for all ImmutableSortedMap instances. It captures the logical contents and they
   * are reconstructed using public factory methods. This ensures that the implementation types
   * remain as implementation details.
   */

    assertNotSame(System.getProperty("java.version"), result.get("java.version"));
  }

  @J2ktIncompatible
  @GwtIncompatible // Maps.fromProperties
  @SuppressWarnings("serial") // never serialized
  public void testFromPropertiesNullKey() {
    Properties properties =
        new Properties() {
          @Override
          public Enumeration<?> propertyNames() {

    assertNotSame(System.getProperty("java.version"), result.get("java.version"));
  }

  @J2ktIncompatible
  @GwtIncompatible // Maps.fromProperties
  @SuppressWarnings("serial") // never serialized
  public void testFromPropertiesNullKey() {
    Properties properties =
        new Properties() {
          @Override
          public Enumeration<?> propertyNames() {

  }

  boolean isHashCodeFast() {
    return false;
  }

  @Override
  public String toString() {
    return Maps.toStringImpl(this);
  }

  /**
   * Serialized type for all ImmutableMap instances. It captures the logical contents and they are
   * reconstructed using public factory methods. This ensures that the implementation types remain
   * as implementation details.
   */

   * @since 7.0
   */
  public static List<Character> charactersOf(CharSequence sequence) {
    return new CharSequenceAsList(checkNotNull(sequence));
  }

  @SuppressWarnings("serial") // serialized using ImmutableList serialization
  private static final class StringAsImmutableList extends ImmutableList<Character> {

    private final String string;

    StringAsImmutableList(String string) {

   *
   * @return the re-serialized object
   * @throws RuntimeException if the specified object was not successfully serialized or
   *     deserialized
   */
  @CanIgnoreReturnValue
  public static <T> T reserialize(T object) {
    return Platform.reserialize(object);
  }

  /**
   * Serializes and deserializes the specified object and verifies that the re-serialized object is

final class SingletonImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {

  // These references are used both by the custom field serializer, and by the
  // GWT compiler to infer the keys and values of the map that needs to be
  // serialized.
  //
  // Although they are non-final, they are package private and the reference is
  // never modified after a map is constructed.
  K singleKey;
  V singleValue;

 * {@link #writeTo} and {@link #readFrom} methods. Both serialized forms will continue to be
 * supported by future versions of this library. However, serial forms generated by newer versions
 * of the code may not be readable by older versions of the code (e.g., a serialized Bloom filter
 * generated today may <i>not</i> be readable by a binary that was compiled 6 months ago).
 *

    return new SerializedForm<>(delegate());
  }

  private void readObject(ObjectInputStream stream) throws InvalidObjectException {
    throw new InvalidObjectException("Use SerializedForm");
  }

  /** Serialized form of the map, to avoid serializing the constraint. */
  private static final class SerializedForm<B extends @Nullable Object> implements Serializable {
    private final Map<Class<? extends @NonNull B>, B> backingMap;

/**
 * Collections of strategies of generating the k * log(M) bits required for an element to be mapped
 * to a BloomFilter of M bits and k hash functions. These strategies are part of the serialized form
 * of the Bloom filters that use them, thus they must be preserved as is (no updates allowed, only
 * introduction of new versions).
 *