return task;
  }

  /**
   * Returns a {@code Future} whose result is taken from the given primary {@code input} or, if the
   * primary input fails with the given {@code exceptionType}, from the result provided by the
   * {@code fallback}. {@link Function#apply} is not invoked until the primary input has failed, so
   * if the primary input succeeds, it is never invoked. If, during the invocation of {@code

 * Character#isHighSurrogate surrogate} {@linkplain Character#isLowSurrogate pairs}, or by starting
 * with short strings already known to be free of unpaired surrogates.
 *
 * <p>The two primary implementations of this interface are {@link CharEscaper} and {@link
 * UnicodeEscaper}. They are heavily optimized for performance and greatly simplify the task of

 * }</pre>
 *
 * you will invoke it depending on the graph representation you're using.
 *
 * <p>If you have an instance of one of the primary {@code common.graph} types ({@link Graph},
 * {@link ValueGraph}, and {@link Network}):
 *
 * <pre>{@code
 * someGraphAlgorithm(startNode, graph);
 * }</pre>
 *

 * public <N> someGraphAlgorithm(N startNode, SuccessorsFunction<N> successorsFunction);
 * }</pre>
 *
 * you will invoke it depending on the graph representation you're using.
 *
 * <p>If you have an instance of one of the primary {@code common.graph} types ({@link Graph},
 * {@link ValueGraph}, and {@link Network}):
 *
 * <pre>{@code
 * someGraphAlgorithm(startNode, graph);
 * }</pre>
 *

 *       cryptographic hashes.)
 *   <li><b>fast:</b> perhaps self-explanatory, but often the most important consideration.
 * </ul>
 *
 * <h3>Providing input to a hash function</h3>
 *
 * <p>The primary way to provide the data that your hash function should act on is via a {@link
 * Hasher}. Obtain a new hasher from the hash function using {@link #newHasher}, "push" the relevant

   * permits? As explained above, there is no unique answer. If we are primarily interested to deal
   * with underutilization, then we want stored permits to be given out /faster/ than fresh ones,
   * because underutilization = free resources for the taking. If we are primarily interested to
   * deal with overflow, then stored permits could be given out /slower/ than fresh ones. Thus, we

 * whose edges have associated non-unique values.
 *
 * <p>A graph is composed of a set of nodes and a set of edges connecting pairs of nodes.
 *
 * <p>There are three primary interfaces provided to represent graphs. In order of increasing
 * complexity they are: {@link Graph}, {@link ValueGraph}, and {@link Network}. You should generally

 * whose edges are anonymous entities with no identity or information of their own.
 *
 * <p>A graph is composed of a set of nodes and a set of edges connecting pairs of nodes.
 *
 * <p>There are three primary interfaces provided to represent graphs. In order of increasing
 * complexity they are: {@link Graph}, {@link ValueGraph}, and {@link Network}. You should generally

 *
 * <p>Operations on this class make no guarantees about the ordering of elements with equal
 * priority. If you need to enforce an ordering, you can define custom classes or comparators that
 * use a secondary key to break ties in primary priority values. For example, here is a class that
 * applies first-in-first-out tie-breaking to comparable elements. To use it, you would insert a
 * {@code new FIFOEntry(anEntry)} instead of a plain entry object.
 *
 * <pre>

  private Closeables() {}

  /**
   * Closes a {@link Closeable}, with control over whether an {@code IOException} may be thrown.
   * This is primarily useful in a finally block, where a thrown exception needs to be logged but
   * not propagated (otherwise the original exception will be lost).
   *