* would declare a return type of `@Nullable T[]`. However, we've decided not to think too hard
   * about arrays for now, as they're a mess. (We previously discussed this in the review of
   * ObjectArrays, which is the main caller of this method.)
   */
  static <T extends @Nullable Object> T[] newArray(T[] reference, int length) {
    T[] empty = reference.length == 0 ? reference : Arrays.copyOf(reference, 0);

   * would declare a return type of `@Nullable T[]`. However, we've decided not to think too hard
   * about arrays for now, as they're a mess. (We previously discussed this in the review of
   * ObjectArrays, which is the main caller of this method.)
   */
  static <T extends @Nullable Object> T[] newArray(T[] reference, int length) {
    T[] empty = reference.length == 0 ? reference : Arrays.copyOf(reference, 0);

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;

import static com.google.common.base.Preconditions.checkPositionIndexes;
import static com.google.common.collect.CollectPreconditions.checkNonnegative;
import static com.google.common.collect.ObjectArrays.checkElementsNotNull;
import static com.google.common.collect.RegularImmutableList.EMPTY;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

         */
        return ObjectArrays.toArrayImpl(delegate());
      }
    }

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

    @Override

         */
        return ObjectArrays.toArrayImpl(delegate());
      }
    }

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

    @Override

      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() {

import static com.google.common.base.Preconditions.checkPositionIndexes;
import static com.google.common.collect.CollectPreconditions.checkNonnegative;
import static com.google.common.collect.ObjectArrays.checkElementsNotNull;
import static com.google.common.collect.RegularImmutableList.EMPTY;
import static java.util.Objects.requireNonNull;

import com.google.common.annotations.GwtCompatible;

   */
  @GwtIncompatible // Array.newInstance(Class, int)
  public static <T extends @Nullable Object> T[] toArray(
      Iterable<? extends T> iterable, Class<@NonNull T> type) {
    return toArray(iterable, ObjectArrays.newArray(type, 0));
  }

  static <T extends @Nullable Object> T[] toArray(Iterable<? extends T> iterable, T[] array) {
    Collection<? extends T> collection = castOrCopyToCollection(iterable);