@Nonnull
    Session getSession();

    @Nonnull
    Collection<ProducedArtifact> getArtifacts();

    @Nonnull
    static ArtifactInstallerRequestBuilder builder() {
        return new ArtifactInstallerRequestBuilder();
    }

    @Nonnull
    static ArtifactInstallerRequest build(Session session, Collection<ProducedArtifact> artifacts) {
        return builder()

     */
    @Nonnull
    ChecksumAlgorithm select(@Nonnull String algorithmName);

    /**
     * Returns a collection of {@link ChecksumAlgorithm} in same order as algorithm names are ordered, or throws if
     * any of the algorithm name is not supported. The returned collection has equal count of elements as passed in
     * collection of names, and if names contains duplicated elements, the returned list of algorithms will have
     * duplicates as well.

    assertTrue("contains(present) should return true", collection.contains(e0()));
  }

  public void testContains_no() {
    assertFalse("contains(notPresent) should return false", collection.contains(e3()));
  }

  @CollectionFeature.Require(ALLOWS_NULL_QUERIES)
  public void testContains_nullNotContainedButQueriesSupported() {
    assertFalse("contains(null) should return false", collection.contains(null));
  }

 * collection instance can only be one size at once.
 *
 * @author George van den Driessche
 */
@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
@GwtCompatible
public enum CollectionSize implements Feature<Collection>, Comparable<CollectionSize> {
  /** Test an empty collection. */
  ZERO(0),
  /** Test a one-element collection. */
  ONE(1),
  /** Test a three-element collection. */
  SEVERAL(3),

  @J2ktIncompatible
  static class SerializedForm implements Serializable {
    final ImmutableCollection<?> collection;

    SerializedForm(ImmutableCollection<?> collection) {
      this.collection = collection;
    }

    Object readResolve() {
      return collection.asList();
    }

    private static final long serialVersionUID = 0;
  }

  @GwtIncompatible // serialization

  public void testToArray_noArgs() {
    Object[] array = collection.toArray();
    expectArrayContentsAnyOrder(createSamplesArray(), array);
  }

  /**
   * {@link Collection#toArray(Object[])} says: "Note that {@code toArray(new Object[0])} is
   * identical in function to {@code toArray()}."
   *
   * <p>For maximum effect, the collection under test should be created from an element array of a

public class CollectionRetainAllTester<E> extends AbstractCollectionTester<E> {

  /** A collection of elements to retain, along with a description for use in failure messages. */
  private class Target {
    private final Collection<E> toRetain;
    private final String description;

    private Target(Collection<E> toRetain, String description) {
      this.toRetain = toRetain;
      this.description = description;
    }

     * .
     */
    @Test
    public void testIsNotEmptyCollectionOfQ() {
        final Collection<String> c = new ArrayList<String>();
        c.add("hoge");
        assertThat(CollectionsUtil.isNotEmpty(c), is(true));
    }

    /**
     * Test method for
     * {@link org.codelibs.core.collection.CollectionsUtil#isEmpty(java.util.Map)}
     * .
     */

  @Override
  Collection<V> wrapCollection(@ParametricNullness K key, Collection<V> collection) {
    return new WrappedSet(key, (Set<V>) collection);
  }

  // Following Javadoc copied from SetMultimap.

  /**
   * {@inheritDoc}
   *
   * <p>Because a {@code SetMultimap} has unique values for a given key, this method returns a
   * {@link Set}, instead of the {@link Collection} specified in the {@link Multimap} interface.
   */
  @Override

  @Override
  Collection<V> wrapCollection(@ParametricNullness K key, Collection<V> collection) {
    return new WrappedSet(key, (Set<V>) collection);
  }

  // Following Javadoc copied from SetMultimap.

  /**
   * {@inheritDoc}
   *
   * <p>Because a {@code SetMultimap} has unique values for a given key, this method returns a
   * {@link Set}, instead of the {@link Collection} specified in the {@link Multimap} interface.
   */
  @Override