- **Collections** (`org.codelibs.core.collection`) - Enhanced collection utilities, array operations, and specialized map/set implementations including LRU caches and case-insensitive collections

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.SortedSet;
import org.jspecify.annotations.NullMarked;

/**
 * Generators of different types of sets and derived collections from sets.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy

    assertPermutationsCount(1, Collections2.permutations(Collections.<Integer>emptyList()));
    assertPermutationsCount(1, Collections2.permutations(newArrayList(1)));
    assertPermutationsCount(2, Collections2.permutations(newArrayList(1, 2)));
    assertPermutationsCount(6, Collections2.permutations(newArrayList(1, 2, 3)));
    assertPermutationsCount(5040, Collections2.permutations(newArrayList(1, 2, 3, 4, 5, 6, 7)));

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.helper;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

      @Override
      <K extends @Nullable Object, V extends @Nullable Object> Map<K, Collection<V>> createMap() {
        return Platform.newHashMapWithExpectedSize(expectedKeys);
      }
    };
  }

  /**
   * Uses a hash table to map keys to value collections.
   *
   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link

      @Override
      <K extends @Nullable Object, V extends @Nullable Object> Map<K, Collection<V>> createMap() {
        return Platform.newHashMapWithExpectedSize(expectedKeys);
      }
    };
  }

  /**
   * Uses a hash table to map keys to value collections.
   *
   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link

            return java.util.Collections.emptyList();
        }

        @Override
        public java.util.List<jakarta.mail.Address> getSavedBccList() {
            return java.util.Collections.emptyList();
        }

        @Override
        public java.util.List<jakarta.mail.Address> getSavedCcList() {
            return java.util.Collections.emptyList();
        }

        @Override

    return emptySet();
  }

  protected Collection<Method> suppressForTreeSetNatural() {
    return emptySet();
  }

  protected Collection<Method> suppressForTreeSetWithComparator() {
    return emptySet();
  }

  protected Collection<Method> suppressForCopyOnWriteArraySet() {
    return Collections.emptySet();
  }

  protected Collection<Method> suppressForUnmodifiableSet() {
    return emptySet();

import static java.util.Arrays.asList;
import static java.util.Collections.emptyList;
import static java.util.Collections.emptySet;
import static java.util.Collections.singletonList;
import static java.util.Collections.unmodifiableList;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.testing.features.CollectionFeature;

    return emptySet();
  }

  private Collection<Method> suppressForEmptySortedMap() {
    return emptySet();
  }

  protected Collection<Method> suppressForSingletonMap() {
    return emptySet();
  }

  protected Collection<Method> suppressForHashMap() {
    return emptySet();
  }

  protected Collection<Method> suppressForHashtable() {