// For discussion of <? extends Object>, see getAllPresent.
  void invalidateAll(Iterable<? extends Object> keys);

  /** Discards all entries in the cache. */
  void invalidateAll();

  /** Returns the approximate number of entries in this cache. */
  long size();

  /**
   * Returns a current snapshot of this cache's cumulative statistics, or a set of default values if

   *
   * @since 8.0
   */
  public static final byte SI = 15;

  /**
   * Data Link Escape: A communication control character which will change the meaning of a limited
   * number of contiguously following characters. It is used exclusively to provide supplementary
   * controls in data communication networks.
   *
   * @since 8.0
   */
  public static final byte DLE = 16;

  /**

    return (valueComparator == null)
        ? new ImmutableSet.Builder<V>()
        : new ImmutableSortedSet.Builder<V>(valueComparator);
  }

  /**
   * @serialData number of distinct keys, and then for each distinct key: the key, the number of
   *     values for that key, and the key's values
   */
  @GwtIncompatible // java.io.ObjectOutputStream
  @J2ktIncompatible

          "it-trace.ch",
          "cool.dk",
          "cool.co.uk",
          "cool.de",
          "cool.es",
          "cool\uFF61fr", // Alternate dot character
          "cool.nl",
          "members.blah.nl.",
          "cool.se",
          "utenti.blah.it",
          "kt.co",
          "a\u7f51\u7edcA.\u7f51\u7edc.Cn" // "a网络A.网络.Cn"
          );

    return create(16);
  }

  /**
   * Constructs a new, empty bimap with the specified expected size.
   *
   * @param expectedSize the expected number of entries
   * @throws IllegalArgumentException if the specified expected size is negative
   */
  public static <K extends @Nullable Object, V extends @Nullable Object> HashBiMap<K, V> create(
      int expectedSize) {

 * strings. This only supports the {@code "%s"} specifier, not the full range of {@link
 * java.util.Formatter} specifiers. However, note that if the number of arguments does not match the
 * number of occurrences of {@code "%s"} in the format string, {@code Preconditions} will still
 * behave as expected, and will still include all argument values in the error message; the message

    assertEquals(TimeUnit.SECONDS, ArbitraryInstances.get(TimeUnit.class));
    assertNotNull(ArbitraryInstances.get(Object.class));
    assertEquals(0, ArbitraryInstances.get(Number.class));
    assertEquals(Charsets.UTF_8, ArbitraryInstances.get(Charset.class));
    assertEquals(Optional.empty(), ArbitraryInstances.get(Optional.class));

    } catch (NullPointerException expected) {
    }
  }

  /**
   * Verify thread safety by using a collection whose size() may be inconsistent with the actual
   * number of elements and whose elements may change over time.
   *
   * <p>This test might fail in GWT because the GWT emulations might count on the input collection

    } catch (NullPointerException expected) {
    }
  }

  /**
   * Verify thread safety by using a collection whose size() may be inconsistent with the actual
   * number of elements and whose elements may change over time.
   *
   * <p>This test might fail in GWT because the GWT emulations might count on the input collection

    // If there are no duplicate keys, hashTablePlus is the final hashTable value. If there *are*
    // duplicate keys, hashTablePlus consists of 3 elements: [0] the hashTable; [1] the number of
    // entries in alternatingKeysAndValues that are still valid after rewriting to remove
    // duplicates; [2] a Builder.DuplicateKey that records the first duplicate key we encountered