* predicate::test}.
 *
 * <p>This interface is now a legacy type. Use {@code java.util.function.Predicate} (or the
 * appropriate primitive specialization such as {@code IntPredicate}) instead whenever possible.
 * Otherwise, at least reduce <i>explicit</i> dependencies on this type by using lambda expressions
 * or method references instead of classes, leaving your code easier to migrate in the future.
 *

  }

  private <T> TypeToken<Iterable<T>> anyIterableType() {
    return new TypeToken<Iterable<T>>() {};
  }

  @SuppressWarnings("rawtypes") // TODO(cpovirk): Can we at least use Class<?> in some places?
  abstract static class TestTypeToInstanceMapGenerator
      implements TestMapGenerator<TypeToken, Object> {

    @Override
    public TypeToken<?>[] createKeyArray(int length) {

            <!-- Even after we stop using JSR305 annotations in our own code, we'll want this link so that NullPointerTester's docs can link to @CheckForNull and friends... at least once we start using this config for guava-testlib. -->
            <offlineLink>
              <url>https://static.javadoc.io/com.google.code.findbugs/jsr305/3.0.1/</url>

    List<byte[]> ordered =
        Arrays.asList(
            new byte[] {},
            new byte[] {LEAST},
            new byte[] {LEAST, LEAST},
            new byte[] {LEAST, (byte) 1},
            new byte[] {(byte) 1},
            new byte[] {(byte) 1, LEAST},
            new byte[] {GREATEST, GREATEST - (byte) 1},
            new byte[] {GREATEST, GREATEST},

    TopKSelector<Integer> top = TopKSelector.least(0);
    for (int i = 0; i < 10; i++) {
      top.offer(i);
    }
    assertThat(top.topK()).isEmpty();
  }

  public void testNoElementsOffered() {
    TopKSelector<Integer> top = TopKSelector.least(10);
    assertThat(top.topK()).isEmpty();
  }

  public void testOfferedFewerThanK() {
    TopKSelector<Integer> top = TopKSelector.least(10);
    top.offer(3);
    top.offer(5);

 *
 * <p>This interface is now a legacy type. Use {@code java.util.function.Predicate} (or the
 * appropriate primitive specialization such as {@code IntPredicate}) instead whenever possible.
 * Otherwise, at least reduce <i>explicit</i> dependencies on this type by using lambda expressions
 * or method references instead of classes, leaving your code easier to migrate in the future.
 *

  }

  private <T> TypeToken<Iterable<T>> anyIterableType() {
    return new TypeToken<Iterable<T>>() {};
  }

  @SuppressWarnings("rawtypes") // TODO(cpovirk): Can we at least use Class<?> in some places?
  abstract static class TestTypeToInstanceMapGenerator
      implements TestMapGenerator<TypeToken, Object> {

    @Override
    public TypeToken<?>[] createKeyArray(int length) {

    return this;
  }

  @CanIgnoreReturnValue
  public MapMaker concurrencyLevel(int concurrencyLevel) {
    checkArgument(
        concurrencyLevel >= 1, "concurrency level (%s) must be at least 1", concurrencyLevel);
    // GWT technically only supports concurrencyLevel == 1, but we silently
    // ignore other positive values.
    return this;
  }

  public <K, V> ConcurrentMap<K, V> makeMap() {

    EnumHashBiMap<Currency, String> bimap = EnumHashBiMap.create(map);
    assertEquals("dollar", bimap.get(Currency.DOLLAR));
    assertEquals(Currency.DOLLAR, bimap.inverse().get("dollar"));

    /* Map must have at least one entry if not an EnumHashBiMap. */
    try {
      EnumHashBiMap.create(Collections.<Currency, String>emptyMap());
      fail("IllegalArgumentException expected");
    } catch (IllegalArgumentException expected) {

      this.elements = elements;
      this.duplicate = duplicate;
    }
  }

  /**
   * @return an array of the proper size with a duplicate element. The size must be at least three.
   */
  protected ArrayWithDuplicate<E> createArrayWithDuplicateElement() {
    E[] elements = createSamplesArray();
    E duplicate = elements[(elements.length / 2) - 1];