*       C}, instance methods are skipped for nulls test.
   *   <li>Nulls test is not performed on method return values unless the method is a visible static
   *       factory method whose return type is {@code C} or {@code C}'s subtype.
   * </ul>
   *
   * <p>In all cases, if {@code C} needs custom logic for testing nulls, you can add an explicit

        current.elemCount = 0;
        // Also clear these fields so that one deleted Entry doesn't retain all elements.
        current.left = null;
        current.right = null;
        current.pred = null;
        current.succ = null;

        current = next;
      }
      successor(header, header);
      rootReference.clear();
    } else {

        // Comprehensive test to verify all methods return expected values
        FessJsonResourceProvider testProvider = new FessJsonResourceProvider();

        // Verify nulls suppression is enabled
        assertTrue("Nulls should be suppressed", testProvider.isNullsSuppressed());

        // Verify pretty print is enabled
        assertFalse("Pretty print should not be suppressed", testProvider.isPrettyPrintSuppressed());

       * we're copying into a `contents` array whose type allows it to contain nulls. Still, it's
       * worth noting that we promise not to put nulls into the array in the first `size` elements.
       * We uphold that promise here because our callers promise that `elements` will not contain
       * nulls in its first `n` elements.
       */
      System.arraycopy(elements, 0, contents, size, n);
      size += n;

   *       C}, instance methods are skipped for nulls test.
   *   <li>Nulls test is not performed on method return values unless the method is a visible static
   *       factory method whose return type is {@code C} or {@code C}'s subtype.
   * </ul>
   *
   * <p>In all cases, if {@code C} needs custom logic for testing nulls, you can add an explicit

 * exceptions whenever it can.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public class MinimalCollection<E extends @Nullable Object> extends AbstractCollection<E> {
  // TODO: expose allow nulls parameter?

  public static <E extends @Nullable Object> MinimalCollection<E> of(E... contents) {
    return new MinimalCollection<>(Object.class, true, contents);
  }

  // TODO: use this

   */
  /*
   * By declaring <T> instead of <T extends @Nullable Object>, we declare this method as requiring a
   * stream whose elements are non-null. However, the method goes out of its way to still handle
   * nulls in the stream. This means that the method can safely be used with a stream that contains
   * nulls as long as the *last* element is *not* null.
   *

 * exceptions whenever it can.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public class MinimalCollection<E extends @Nullable Object> extends AbstractCollection<E> {
  // TODO: expose allow nulls parameter?

  public static <E extends @Nullable Object> MinimalCollection<E> of(E... contents) {
    return new MinimalCollection<>(Object.class, true, contents);
  }

  // TODO: use this

   */
  @Nullable V getLiveValue(ReferenceEntry<K, V> entry, long now) {
    if (entry.getKey() == null) {
      return null;
    }
    V value = entry.getValueReference().get();
    if (value == null) {
      return null;
    }

    if (isExpired(entry, now)) {
      return null;
    }
    return value;
  }

  // expiration

   */
  @Nullable V getLiveValue(ReferenceEntry<K, V> entry, long now) {
    if (entry.getKey() == null) {
      return null;
    }
    V value = entry.getValueReference().get();
    if (value == null) {
      return null;
    }

    if (isExpired(entry, now)) {
      return null;
    }
    return value;
  }

  // expiration