@IgnoreJRERequirement
  public java.util.Optional<T> toJavaUtil() {
    return java.util.Optional.ofNullable(orNull());
  }

  Optional() {}

  /**
   * Returns {@code true} if this holder contains a (non-null) instance.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> no differences.
   */
  public abstract boolean isPresent();

  /**

import java.lang.reflect.Method;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.EnumSet;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentSkipListSet;

 */

package com.google.common.util.concurrent;

import static com.google.common.util.concurrent.Service.State.FAILED;
import static com.google.common.util.concurrent.Service.State.NEW;
import static com.google.common.util.concurrent.Service.State.RUNNING;
import static com.google.common.util.concurrent.Service.State.STARTING;
import static com.google.common.util.concurrent.Service.State.STOPPING;

 * under the License.
 */
package org.apache.maven.cling.invoker;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.function.Consumer;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.DeprecatedAttributes;

import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Comparator;
import java.util.Currency;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import java.util.NavigableMap;

 */

package com.google.common.util.concurrent.testing;

import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static org.junit.Assert.assertThrows;

import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.ListeningScheduledExecutorService;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.CancellationException;

import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.AbstractCollectionTester;
import com.google.common.collect.testing.MinimalCollection;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;
import java.util.Collection;
import java.util.Collections;

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

import java.nio.file.Path;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Optional;

import org.apache.maven.api.Artifact;
import org.apache.maven.api.ProducedArtifact;
import org.apache.maven.api.Project;
import org.apache.maven.api.ProjectScope;

import assertk.assertThat
import assertk.assertions.isCloseTo
import assertk.assertions.isFalse
import assertk.assertions.isInstanceOf
import assertk.assertions.matchesPredicate
import java.util.Deque
import java.util.concurrent.ConcurrentLinkedDeque
import java.util.concurrent.TimeUnit
import okhttp3.ConnectionEvent.NoNewExchanges
import okhttp3.internal.connection.RealConnection
import okio.IOException
import org.junit.jupiter.api.Assertions

package org.codelibs.fess.app.web.api.admin.labeltype;

import static org.codelibs.core.stream.StreamUtil.stream;
import static org.codelibs.fess.app.web.admin.labeltype.AdminLabeltypeAction.getLabelType;

import java.util.List;
import java.util.stream.Collectors;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.core.lang.StringUtil;
import org.codelibs.fess.Constants;