*
   * <p><b>{@code Stream} equivalent:</b> {@code stream.filter(predicate).findFirst()}.
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final Optional<@NonNull E> firstMatch(Predicate<? super E> predicate) {
    return Iterables.<E>tryFind((Iterable<@NonNull E>) getDelegate(), predicate);
  }

  /**

   *
   * <p><b>{@code Stream} equivalent:</b> {@code stream.filter(predicate).findFirst()}.
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final Optional<@NonNull E> firstMatch(Predicate<? super E> predicate) {
    return Iterables.<E>tryFind((Iterable<@NonNull E>) getDelegate(), predicate);
  }

  /**