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.collect.testing.testers.CollectionSerializationEqualTester;
import com.google.common.testing.SerializableTester;
import java.util.ArrayList;
import java.util.Collection;
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;

/**

 */
package org.apache.maven;

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

import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Set;

import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.ArtifactUtils;

    }

    public Set<PropertyMetaData> getDeclaredProperties() {
        return new HashSet<PropertyMetaData>(declaredProperties.values());
    }

    public Set<MethodMetaData> getDeclaredMethods() {
        return declaredMethods;
    }

    public Set<String> getDeclaredMethodNames() {
        Set<String> names = new HashSet<String>();
        for (MethodMetaData declaredMethod : declaredMethods) {

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.concurrent.atomic.AtomicInteger;

import org.codelibs.fess.suggest.Suggester;

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.extension.internal;

import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.codehaus.plexus.classworlds.realm.ClassRealm;

import static java.util.function.Function.identity;
import static java.util.stream.Collectors.collectingAndThen;

                Set<Thread> threadsAfter = new HashSet<>(Thread.getAllStackTraces().keySet());
                threadsAfter.removeAll(threadsBefore);

                Set<Thread> leaked = new HashSet<>();
                for ( Thread t : threadsAfter ) {
                    if ( t.getName().startsWith("Transport") ) {

        this.scopes = new HashSet<>();

        addScopes(scopes);
    }

    /**
     * Creates a new filter that combines the specified filters.
     *
     * @param filters The filters to combine, may be {@code null}.
     */
    public CumulativeScopeArtifactFilter(CumulativeScopeArtifactFilter... filters) {
        this.scopes = new HashSet<>();

        if (filters != null) {

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.model.interpolation;

import java.util.HashSet;
import java.util.Set;

import org.apache.maven.model.path.UrlNormalizer;
import org.codehaus.plexus.interpolation.InterpolationPostProcessor;

/**

        Set<String> roleSet = new HashSet<>();
        roleQueryHelperImpl.processParameter(request, roleSet);
        return roleSet;
    }

    private Set<String> buildByHeader(final RoleQueryHelper roleQueryHelperImpl, final HttpServletRequest request) {
        Set<String> roleSet = new HashSet<>();
        roleQueryHelperImpl.processHeader(request, roleSet);
        return roleSet;