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,

    /**
     * Creates and returns a new instance of {@link HashSet}.
     *
     * @param <E> the element type of {@link HashSet}
     * @return a new instance of {@link HashSet}
     * @see HashSet#HashSet()
     */
    public static <E> HashSet<E> newHashSet() {
        return new HashSet<>();
    }

    /**
     * Creates and returns a new instance of {@link HashSet}.
     *

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
import java.util.Base64;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import org.apache.commons.lang3.StringUtils;
import org.apache.logging.log4j.LogManager;

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.util;

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

import org.codelibs.fess.opensearch.user.bsentity.BsUser;
import org.codelibs.fess.unit.UnitFessTestCase;

import org.jspecify.annotations.Nullable;

/**
 * An abstract implementation of {@link Hasher}, which only requires subtypes to implement {@link
 * #putByte}. Subtypes may provide more efficient implementations, however.
 *
 * @author Dimitris Andreou
 */
abstract class AbstractHasher implements Hasher {
  @Override
  @CanIgnoreReturnValue
  public final Hasher putBoolean(boolean b) {
    return putByte(b ? (byte) 1 : (byte) 0);
  }

  protected void update(byte[] b) {
    update(b, 0, b.length);
  }

  /** Updates this hasher with {@code len} bytes starting at {@code off} in the given buffer. */
  protected void update(byte[] b, int off, int len) {
    for (int i = off; i < off + len; i++) {
      update(b[i]);
    }
  }

  /** Updates this hasher with bytes from the given buffer. */
  protected void update(ByteBuffer b) {

    assertEquals("[" + JOINER.join(map.keySet()) + "]", map.keySet().toString());
    assertEquals("[" + JOINER.join(map.values()) + "]", map.values().toString());

    assertEquals(new HashSet<>(map.entrySet()), map.entrySet());
    assertEquals(new HashSet<>(map.keySet()), map.keySet());
  }

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;

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;

/**

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;

/**