* can be used in the testers.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@NullMarked
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], asList(contents));
  }

 * can be used in the testers.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@NullMarked
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], asList(contents));
  }

              @Override
              protected Set<String> create(String[] elements) {
                return MinimalSet.of(elements);
              }
            })
        .named("MinimalSet")
        .withFeatures(
            CollectionFeature.ALLOWS_NULL_VALUES, CollectionFeature.NONE, CollectionSize.ANY)
        .createTestSuite();
  }

                  @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());

            + " 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(

import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.MinimalSet;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

              @Override
              protected Set<String> create(String[] elements) {
                return MinimalSet.of(elements);
              }
            })
        .named("MinimalSet")
        .withFeatures(
            CollectionFeature.ALLOWS_NULL_VALUES, CollectionFeature.NONE, CollectionSize.ANY)
        .createTestSuite();
  }

                  @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());

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.HashSet;
import java.util.Map;
import java.util.Map.Entry;
import org.jspecify.annotations.NullUnmarked;

@GwtCompatible
@NullUnmarked