return _columnUserSessionId;
    }

    public ColumnInfo columnVirtualHost() {
        return _columnVirtualHost;
    }

    protected List<ColumnInfo> ccil() {
        List<ColumnInfo> ls = newArrayList();
        ls.add(columnAccessType());
        ls.add(columnClientIp());
        ls.add(columnHitCount());
        ls.add(columnHitCountRelation());
        ls.add(columnLanguages());

        return _columnUserAgent;
    }

    public ColumnInfo columnVirtualHosts() {
        return _columnVirtualHosts;
    }

    protected List<ColumnInfo> ccil() {
        List<ColumnInfo> ls = newArrayList();
        ls.add(columnAvailable());
        ls.add(columnBoost());
        ls.add(columnConfigParameter());
        ls.add(columnCreatedBy());
        ls.add(columnCreatedTime());
        ls.add(columnDepth());

    Supplier<ArrayList<Integer>> listSupplier =
        new Supplier<ArrayList<Integer>>() {
          @Override
          public ArrayList<Integer> get() {
            return Lists.newArrayList(0);
          }
        };

    Function<List<Integer>, List<Integer>> addElementFunction =
        new Function<List<Integer>, List<Integer>>() {
          @Override

    Supplier<ArrayList<Integer>> listSupplier =
        new Supplier<ArrayList<Integer>>() {
          @Override
          public ArrayList<Integer> get() {
            return Lists.newArrayList(0);
          }
        };

    Function<List<Integer>, List<Integer>> addElementFunction =
        new Function<List<Integer>, List<Integer>>() {
          @Override

   */
  private static <E extends @Nullable Object> Collection<E> castOrCopyToCollection(
      Iterable<E> iterable) {
    return (iterable instanceof Collection)
        ? (Collection<E>) iterable
        : Lists.newArrayList(iterable.iterator());
  }

  /**
   * Adds all elements in {@code iterable} to {@code collection}.
   *
   * @return {@code true} if {@code collection} was modified as a result of this operation.
   */

     *
     * @param <E> the element type of {@link ArrayList}
     * @return a new instance of {@link ArrayList}
     * @see ArrayList#ArrayList()
     */
    public static <E> ArrayList<E> newArrayList() {
        return new ArrayList<>();
    }

    /**
     * Creates and returns a new instance of {@link ArrayList}.
     *
     * @param <E> the element type of {@link ArrayList}

@GwtCompatible
@NullMarked
public class Helpers {
  // Clone of Objects.equals
  static boolean equal(@Nullable Object a, @Nullable Object b) {
    return a == b || (a != null && a.equals(b));
  }

  // Clone of Lists.newArrayList
  public static <E extends @Nullable Object> List<E> copyToList(Iterable<? extends E> elements) {
    List<E> list = new ArrayList<>();
    addAll(list, elements);
    return list;
  }

 * governing permissions and limitations under the License.
 */
package org.codelibs.core.collection;

import static org.codelibs.core.collection.CollectionsUtil.newArrayList;
import static org.codelibs.core.misc.AssertionUtil.assertArgument;
import static org.codelibs.core.misc.AssertionUtil.assertArgumentNotNull;

import java.lang.reflect.Array;
import java.math.BigDecimal;

@GwtCompatible
@NullMarked
public class Helpers {
  // Clone of Objects.equals
  static boolean equal(@Nullable Object a, @Nullable Object b) {
    return a == b || (a != null && a.equals(b));
  }

  // Clone of Lists.newArrayList
  public static <E extends @Nullable Object> List<E> copyToList(Iterable<? extends E> elements) {
    List<E> list = new ArrayList<>();
    addAll(list, elements);
    return list;
  }

    List<@Nullable String> listWithNull = Lists.newArrayList((String) null);
    assertThrows(
        NullPointerException.class,
        () -> Maps.uniqueIndex((List<String>) listWithNull, Functions.constant(1)));
  }

  /** Null keys aren't allowed either. */
  public void testUniqueIndexNullKey() {
    List<String> oneStringList = Lists.newArrayList("foo");
    assertThrows(
        NullPointerException.class,