synchronized (collection) { // to allow Collections.synchronized* tests to pass
      Helpers.assertEqualIgnoringOrder(
          getSampleElements(), Arrays.asList(collection.stream().toArray()));
    }
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testStreamToArrayKnownOrder() {
    synchronized (collection) { // to allow Collections.synchronized* tests to pass

  /** The HTTP {@code Access-Control-Allow-Headers} header field name. */
  public static final String ACCESS_CONTROL_ALLOW_HEADERS = "Access-Control-Allow-Headers";
  /** The HTTP {@code Access-Control-Allow-Methods} header field name. */
  public static final String ACCESS_CONTROL_ALLOW_METHODS = "Access-Control-Allow-Methods";
  /** The HTTP {@code Access-Control-Allow-Origin} header field name. */

 * user-defined properties.
 *
 * <p>A {@code Network} built by this class has the following default properties:
 *
 * <ul>
 *   <li>does not allow parallel edges
 *   <li>does not allow self-loops
 *   <li>orders {@link Network#nodes()} and {@link Network#edges()} in the order in which the
 *       elements were added (insertion order)
 * </ul>
 *

  // The fake cast to E is safe because the creation methods only allow E's
  @Override
  @SuppressWarnings("unchecked")
  public E get(int index) {
    return (E) array[index];
  }

  @SuppressWarnings("unchecked")
  @Override
  public UnmodifiableListIterator<E> listIterator(int index) {
    // for performance
    // The fake cast to E is safe because the creation methods only allow E's

    GraphBuilder<N1> castBuilder = cast();
    return new ImmutableGraph.Builder<>(castBuilder);
  }

  /**
   * Specifies whether the graph will allow self-loops (edges that connect a node to itself).
   * Attempting to add a self-loop to a graph that does not allow them will throw an {@link
   * UnsupportedOperationException}.
   *
   * <p>The default value is {@code false}.
   */
  @CanIgnoreReturnValue

    GraphBuilder<N1> castBuilder = cast();
    return new ImmutableGraph.Builder<>(castBuilder);
  }

  /**
   * Specifies whether the graph will allow self-loops (edges that connect a node to itself).
   * Attempting to add a self-loop to a graph that does not allow them will throw an {@link
   * UnsupportedOperationException}.
   *
   * <p>The default value is {@code false}.
   */
  @CanIgnoreReturnValue

    ValueGraphBuilder<N1, V1> castBuilder = cast();
    return new ImmutableValueGraph.Builder<>(castBuilder);
  }

  /**
   * Specifies whether the graph will allow self-loops (edges that connect a node to itself).
   * Attempting to add a self-loop to a graph that does not allow them will throw an {@link
   * UnsupportedOperationException}.
   *
   * <p>The default value is {@code false}.
   */
  @CanIgnoreReturnValue

   * better approach is to /allow/ the request right away (as if it was an acquire(1) request
   * instead), and postpone /subsequent/ requests as needed. In this version, we allow starting the
   * task immediately, and postpone by 100 seconds future requests, thus we allow for work to get
   * done in the meantime instead of waiting idly.
   *

/**
 * Exception indicating that a recursive delete can't be performed because the file system does not
 * have the support necessary to guarantee that it is not vulnerable to race conditions that would
 * allow it to delete files and directories outside of the directory being deleted (i.e., {@link
 * SecureDirectoryStream} is not supported).
 *

 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
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