/**
   * A helper to create a new {@code ListenableFuture} whose result is generated from a combination
   * of input futures.
   *
   * <p>See {@link #whenAllComplete} and {@link #whenAllSucceed} for how to instantiate this class.
   *
   * <p>Example:
   *
   * {@snippet :
   * final ListenableFuture<Instant> loginDateFuture =
   *     loginService.findLastLoginDate(username);

import java.util.concurrent.SynchronousQueue;

/**
 * Utility class for collections.
 *
 * @author koichik
 */
public abstract class CollectionsUtil {

    /**
     * Do not instantiate.
     */
    protected CollectionsUtil() {
    }

    /**
     * Creates and returns a new instance of {@link ArrayBlockingQueue}.
     *
     * @param <E> the element type of {@link ArrayBlockingQueue}

  /**
   * A builder of a {@link ClosingFuture} step that is derived from more than one input step.
   *
   * <p>See {@link #whenAllComplete(Iterable)} and {@link #whenAllSucceed(Iterable)} for how to
   * instantiate this class.
   *
   * <p>Example:
   *
   * {@snippet :
   * final ClosingFuture<BufferedReader> file1ReaderFuture = ...;
   * final ClosingFuture<BufferedReader> file2ReaderFuture = ...;