*
 * @author Regina O'Dell
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class MinimalSet<E extends @Nullable Object> extends MinimalCollection<E> implements Set<E> {

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> of(E... contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], Arrays.asList(contents));
  }

 *
 * @author Regina O'Dell
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class MinimalSet<E extends @Nullable Object> extends MinimalCollection<E> implements Set<E> {

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> of(E... contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], Arrays.asList(contents));
  }

/**
 * Unit test for {@link MinimalSet}.
 *
 * @author Regina O'Dell
 */
public class MinimalSetTest extends TestCase {
  public static Test suite() {
    return SetTestSuiteBuilder.using(
            new TestStringSetGenerator() {
              @Override
              protected Set<String> create(String[] elements) {
                return MinimalSet.of(elements);
              }
            })

            + " even if some elements are null.",
        getSet().equals(MinimalSet.from(elements)));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_otherContainsNull() {
    Collection<E> elements = getSampleElements(getNumElements() - 1);
    elements.add(null);
    Set<E> other = MinimalSet.from(elements);

    assertFalse(

            + " even if some elements are null.",
        getSet().equals(MinimalSet.from(elements)));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_otherContainsNull() {
    Collection<E> elements = getSampleElements(getNumElements() - 1);
    elements.add(null);
    Set<E> other = MinimalSet.from(elements);

    assertFalse(

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Joiner;
import com.google.common.collect.testing.MapInterfaceTest;
import com.google.common.collect.testing.MinimalSet;
import java.util.Map;
import java.util.Map.Entry;

@GwtCompatible
abstract class AbstractImmutableMapMapInterfaceTest<K, V> extends MapInterfaceTest<K, V> {
  AbstractImmutableMapMapInterfaceTest() {

                  @Override
                  protected Set<String> create(String[] elements) {
                    return new StandardImplForwardingSet<>(MinimalSet.of(elements));
                  }
                })
            .named("ForwardingSet[MinimalSet] with standard implementations")
            .withFeatures(CollectionSize.ANY, CollectionFeature.ALLOWS_NULL_VALUES)
            .createTestSuite());

/**
 * Unit test for {@link MinimalSet}.
 *
 * @author Regina O'Dell
 */
public class MinimalSetTest extends TestCase {
  public static Test suite() {
    return SetTestSuiteBuilder.using(
            new TestStringSetGenerator() {
              @Override
              protected Set<String> create(String[] elements) {
                return MinimalSet.of(elements);
              }
            })

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Joiner;
import com.google.common.collect.testing.MapInterfaceTest;
import com.google.common.collect.testing.MinimalSet;
import java.util.Map;
import java.util.Map.Entry;

@GwtCompatible
abstract class AbstractImmutableMapMapInterfaceTest<K, V> extends MapInterfaceTest<K, V> {
  AbstractImmutableMapMapInterfaceTest() {

                  @Override
                  protected Set<String> create(String[] elements) {
                    return new StandardImplForwardingSet<>(MinimalSet.of(elements));
                  }
                })
            .named("ForwardingSet[MinimalSet] with standard implementations")
            .withFeatures(CollectionSize.ANY, CollectionFeature.ALLOWS_NULL_VALUES)
            .createTestSuite());