## Adding Guava to your build

Guava's Maven group ID is `com.google.guava`, and its artifact ID is `guava`.
Guava provides two different "flavors": one for use on a (Java 8+) JRE and one
for use on Android or by any library that wants to be compatible with Android.
These flavors are specified in the Maven version field as either `33.4.8-jre` or
`33.4.8-android`. For more about depending on Guava, see

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;

    assertNull(navigableSet.pollLast());
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testSingletonSetPollFirst() {
    assertEquals(a, navigableSet.pollFirst());
    assertTrue(navigableSet.isEmpty());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonSetNearby() {
    assertNull(navigableSet.lower(e0()));
    assertEquals(a, navigableSet.floor(e0()));

    super(false, true, true, true, true);
  }

  @Override
  protected SortedMap<String, Integer> makePopulatedMap() {
    NavigableMap<String, Integer> map = new SafeTreeMap<>();
    map.put("one", 1);
    map.put("two", 2);
    map.put("three", 3);
    return SerializableTester.reserialize(map);
  }

  @Override
  protected SortedMap<String, Integer> makeEmptyMap() throws UnsupportedOperationException {

                    return union(singleton(elements[0]), singleton(elements[0]));
                  }
                })
            .named("singleton U itself")
            .withFeatures(CollectionSize.ONE, CollectionFeature.ALLOWS_NULL_VALUES)
            .createTestSuite());

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override

  private static final Integer I1 = -1;
  private static final Integer I2 = 3;
  private static final String S0 = "3";
  private static final String S1 = "Ninety five";
  private static final String S2 = "44 one million";
  private static final String S3 = "Lowly laundry lefties";
  private static final String S4 = "89273487U#*&#";
  private static final Double D0 = 9.234d;
  private static final Double D1 = -1.2e55;

  @Benchmark

  /**
   * Indicates that the constructor or factory method of a map, usually an immutable map, throws an
   * {@link IllegalArgumentException} when presented with duplicate keys instead of discarding all
   * but one.
   */
  REJECTS_DUPLICATES_AT_CREATION,

  GENERAL_PURPOSE(SUPPORTS_PUT, SUPPORTS_REMOVE);

  private final Set<Feature<? super Map>> implied;

  MapFeature(Feature<? super Map>... implied) {

    @Override
    public BigInteger next(BigInteger value) {
      return value.add(BigInteger.ONE);
    }

    @Override
    public BigInteger previous(BigInteger value) {
      return value.subtract(BigInteger.ONE);
    }

    @Override
    BigInteger offset(BigInteger origin, long distance) {
      checkNonnegative(distance, "distance");

    extends AbstractImmutableMapMapInterfaceTest<String, Integer> {
  @Override
  protected Map<String, Integer> makePopulatedMap() {
    return ImmutableMap.of("one", 1);
  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "minus one";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return -1;
  }

    extends AbstractImmutableSortedMapMapInterfaceTest<String, Integer> {
  @Override
  protected SortedMap<String, Integer> makePopulatedMap() {
    return ImmutableSortedMap.of("one", 1);
  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "minus one";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return -1;
  }