@Override
      public @Nullable Object[] toArray() {
        return ObjectArrays.toArrayImpl(this);
      }

      @Override
      @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
      public <T extends @Nullable Object> T[] toArray(T[] a) {
        return ObjectArrays.toArrayImpl(this, a);
      }

      @Override
      public Spliterator<K> spliterator() {

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ObjectArrays;
import com.google.common.collect.testing.ListTestSuiteBuilder;
import com.google.common.collect.testing.SampleElements;
import com.google.common.collect.testing.TestListGenerator;

  public Object[] toArray() {
    /*
     * ObjectArrays.toArrayImpl returns `@Nullable Object[]` rather than `Object[]` but only because
     * it can be used with collections that may contain null. This collection is a collection of
     * non-null elements, so we can treat it as a plain `Object[]`.
     */
    @SuppressWarnings("nullness")
    Object[] result = ObjectArrays.toArrayImpl(this);
    return result;
  }

import static java.nio.charset.StandardCharsets.UTF_8;
import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
import static org.junit.Assert.assertThrows;

import com.google.common.collect.ObjectArrays;
import com.google.common.jimfs.Configuration;
import com.google.common.jimfs.Feature;
import com.google.common.jimfs.Jimfs;
import java.io.IOException;
import java.nio.file.FileAlreadyExistsException;

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.util.concurrent;

import com.google.common.collect.ObjectArrays;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.AbstractQueue;
import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.Iterator;

import static java.nio.charset.StandardCharsets.UTF_8;
import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
import static org.junit.Assert.assertThrows;

import com.google.common.collect.ObjectArrays;
import com.google.common.jimfs.Configuration;
import com.google.common.jimfs.Feature;
import com.google.common.jimfs.Jimfs;
import java.io.IOException;
import java.nio.file.FileAlreadyExistsException;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ObjectArrays;
import com.google.common.collect.testing.ListTestSuiteBuilder;
import com.google.common.collect.testing.SampleElements;
import com.google.common.collect.testing.TestListGenerator;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ObjectArrays;
import com.google.common.collect.testing.ListTestSuiteBuilder;
import com.google.common.collect.testing.SampleElements;
import com.google.common.collect.testing.TestListGenerator;

 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.ObjectArrays.checkElementsNotNull;

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;

      if (a.length > 0) {
        a[0] = null;
      }
      return a;
    }
    Set<E> delegate = delegateOrNull();
    return (delegate != null)
        ? delegate.toArray(a)
        : ObjectArrays.toArrayImpl(requireElements(), 0, size, a);
  }

  /**
   * Ensures that this {@code CompactHashSet} has the smallest representation in memory, given its
   * current size.
   */
  public void trimToSize() {