* result of a <i>future</i> call to {@code next()}.
   */
  protected abstract @Nullable T computeNext(T previous);

  @Override
  public final boolean hasNext() {
    return nextOrNull != null;
  }

  @Override
  public final T next() {
    if (nextOrNull == null) {
      throw new NoSuchElementException();
    }
    T oldNext = nextOrNull;
    nextOrNull = computeNext(oldNext);

 * 3: "Enforce the singleton property with a private constructor or an enum type". For example:
 *
 * {@snippet :
 * public enum PersonFunnel implements Funnel<Person> {
 *   INSTANCE;
 *   public void funnel(Person person, PrimitiveSink into) {
 *     into.putUnencodedChars(person.getFirstName())
 *         .putUnencodedChars(person.getLastName())
 *         .putInt(person.getAge());

  }

  @Override
  @ParametricNullness
  public final T next() {
    if (!hasNext()) {
      throw new NoSuchElementException();
    }
    state = State.NOT_READY;
    // Safe because hasNext() ensures that tryToComputeNext() has put a T into `next`.
    T result = uncheckedCastNullableTToT(next);
    next = null;
    return result;
  }

  @Override
  public final void remove() {

package org.apache.maven.api;

import java.io.File;
import java.nio.file.Path;
import java.util.List;

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class JavaPathTypeTest {
    /**
     * {@return dummy paths to use in tests}.
     */
    private static List<Path> paths() {
        return List.of(Path.of("src", "foo.java"), Path.of("src", "bar.java"));
    }

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *

/**
 * Action class for handling thumbnail image requests.
 * Serves thumbnail images for documents in the search results.
 */
public class ThumbnailAction extends FessSearchAction {

    /**
     * Default constructor for ThumbnailAction.
     */
    public ThumbnailAction() {
        super();
    }

    // ===================================================================================