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,

            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());
  }

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;

/**

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;

/**

import static org.hamcrest.CoreMatchers.not;
import static org.hamcrest.CoreMatchers.notNullValue;
import static org.junit.Assert.assertThat;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import junit.framework.TestCase;
import junit.textui.ResultPrinter;
import junit.textui.TestRunner;

import org.codelibs.core.io.TraversalUtil.FileSystemTraverser;

                if (key.getRawType() == List.class) {
                    Set<Binding<Object>> res2 = getBindings(key.getTypeParameter(0));
                    Set<Binding<Object>> res3 = res2 != null ? new HashSet<>(res2) : new HashSet<>();
                    try {
                        List<Object> l = containerProvider
                                .get()
                                .lookupList(key.getTypeParameter(0).getRawType());

import javax.inject.Inject;
import javax.inject.Named;

import java.io.File;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;

import org.apache.maven.RepositoryUtils;

        HashSet<String> exportedPackages = new HashSet<String>();
        exportedPackages.add("group1:artifact1");

        return new DefaultClassRealmManager(
                new DefaultCoreRealm(container),
                new ArrayList<ClassRealmManagerDelegate>(),
                new CoreExports(new ClassRealm(null, "test", null), new HashSet<String>(), exportedPackages));
    }