new TestStringSetGenerator() {
              @Override
              public Set<String> create(String[] elements) {
                return new HashSet<>(MinimalCollection.of(elements));
              }
            })
        .named("HashSet")
        .withFeatures(
            SetFeature.GENERAL_PURPOSE,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.ALLOWS_NULL_VALUES,

    Set<String> all = Sets.union(friends, enemies);
    assertEquals(5, all.size());

    ImmutableSet<String> immut = Sets.union(friends, enemies).immutableCopy();
    HashSet<String> mut = Sets.union(friends, enemies).copyInto(new HashSet<String>());

    enemies.add("Buck");
    assertEquals(6, all.size());
    assertEquals(5, immut.size());
    assertEquals(5, mut.size());
  }

    Set<String> all = Sets.union(friends, enemies);
    assertEquals(5, all.size());

    ImmutableSet<String> immut = Sets.union(friends, enemies).immutableCopy();
    HashSet<String> mut = Sets.union(friends, enemies).copyInto(new HashSet<String>());

    enemies.add("Buck");
    assertEquals(6, all.size());
    assertEquals(5, immut.size());
    assertEquals(5, mut.size());
  }

            new TestStringSetGenerator() {
              @Override
              public Set<String> create(String[] elements) {
                return new HashSet<>(MinimalCollection.of(elements));
              }
            })
        .named("HashSet")
        .withFeatures(
            SetFeature.GENERAL_PURPOSE,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.ALLOWS_NULL_VALUES,

import com.google.common.testing.SerializableTester;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import junit.framework.TestSuite;

/**

      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {
        return Collections.unmodifiableSet(new HashSet<E>(contents));
      }
    },
    SynchronizedSetImpl {
      @Override
      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {
        return Collections.synchronizedSet(new HashSet<E>(contents));
      }
    },
    ImmutableSetImpl {
      @Override

      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {
        return Collections.unmodifiableSet(new HashSet<E>(contents));
      }
    },
    SynchronizedSetImpl {
      @Override
      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {
        return Collections.synchronizedSet(new HashSet<E>(contents));
      }
    },
    ImmutableSetImpl {
      @Override

import com.google.common.testing.SerializableTester;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.function.BiPredicate;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

        expectedEntrySetHash += expectedHash;
      }
      assertEquals(expectedEntrySetHash, entrySet.hashCode());
      assertTrue(entrySet.containsAll(new HashSet<Entry<K, V>>(entrySet)));
      assertTrue(entrySet.equals(new HashSet<Entry<K, V>>(entrySet)));
    }

    Object[] entrySetToArray1 = entrySet.toArray();
    assertEquals(map.size(), entrySetToArray1.length);

  }

  public void testNewHashSetEmpty() {
    HashSet<Integer> set = Sets.newHashSet();
    verifySetContents(set, EMPTY_COLLECTION);
  }

  public void testNewHashSetVarArgs() {
    HashSet<Integer> set = Sets.newHashSet(0, 1, 1);
    verifySetContents(set, Arrays.asList(0, 1));
  }

  public void testNewHashSetFromCollection() {
    HashSet<Integer> set = Sets.newHashSet(SOME_COLLECTION);