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 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;

    }

    /**
     * {@link HashSet}の新しいインスタンスを作成して返します。
     *
     * @param <E>
     *            {@link HashSet}の要素型
     * @return {@link HashSet}の新しいインスタンス
     * @see HashSet#HashSet()
     */
    public static <E> HashSet<E> newHashSet() {
        return new HashSet<>();
    }

    /**
     * {@link HashSet}の新しいインスタンスを作成して返します。
     *
     * @param <E>

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;

/**

            Collection<Profile> profiles, ProfileActivationContext context, ModelProblemCollector problems) {
        Collection<String> activatedIds = new HashSet<>(context.getActiveProfileIds());
        Collection<String> deactivatedIds = new HashSet<>(context.getInactiveProfileIds());

        List<Profile> activeProfiles = new ArrayList<>(profiles.size());
        List<Profile> activePomProfilesByDefault = new ArrayList<>();

 */
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;

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

import java.util.HashSet;

import org.apache.maven.execution.MavenSession;
import org.apache.maven.lifecycle.MavenExecutionPlan;
import org.apache.maven.lifecycle.internal.ExecutionEventCatapult;

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

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

import org.apache.maven.execution.ProjectDependencyGraph;
import org.apache.maven.lifecycle.internal.ProjectBuildList;

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;

/**