*
   * <p>Although all tasks are immediately executed in the thread that submitted the task, this
   * {@code ExecutorService} imposes a small locking overhead on each task submission in order to
   * implement shutdown and termination behavior.
   *
   * <p>Because of the nature of single-thread execution, the methods {@code scheduleAtFixedRate}
   * and {@code scheduleWithFixedDelay} are not supported by this class and will throw an

    int i = 0;
    for (Object e : elements) {
      array[i++] = (UnhashableObject) e;
    }
    return create(array);
  }

  /**
   * Creates a new collection containing the given elements; implement this method instead of {@link
   * #create(Object...)}.
   */
  protected abstract T create(UnhashableObject[] elements);

  @Override
  public UnhashableObject[] createArray(int length) {

 * effort required to implement this interface.
 *
 * <p>To implement a cache, the programmer needs only to extend this class and provide an
 * implementation for the {@link #get(Object)} and {@link #getIfPresent} methods. {@link
 * #getUnchecked}, {@link #get(Object, Callable)}, and {@link #getAll} are implemented in terms of
 * {@code get}; {@link #getAllPresent} is implemented in terms of {@code getIfPresent}; {@link

 * effort required to implement this interface.
 *
 * <p>To implement a cache, the programmer needs only to extend this class and provide an
 * implementation for the {@link #get(Object)} and {@link #getIfPresent} methods. {@link
 * #getUnchecked}, {@link #get(Object, Callable)}, and {@link #getAll} are implemented in terms of
 * {@code get}; {@link #getAllPresent} is implemented in terms of {@code getIfPresent}; {@link

 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p>This class does not implement {@link java.util.RandomAccess}. If the delegate supports random
 * access, the {@code ForwardingList} subclass should implement the {@code RandomAccess} interface.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingList} forward <b>indiscriminately</b> to the

import java.util.Map;
import java.util.concurrent.Executor;

/**
 * Computes or retrieves values, based on a key, for use in populating a {@link LoadingCache}.
 *
 * <p>Most implementations will only need to implement {@link #load}. Other methods may be
 * overridden as desired.
 *
 * <p>Usage example:
 *
 * <pre>{@code
 * CacheLoader<Key, Graph> loader = new CacheLoader<Key, Graph>() {

   * AnnotatedElement}, which {@code TypeVariable} began to extend only in Java 8. Those methods
   * refer only to types present in Java 7, so we could implement them in {@code TypeVariableImpl}
   * today. (We could probably then make {@code TypeVariableImpl} implement {@code AnnotatedElement}
   * so that we get partial compile-time checking.)
   *

      int i = 0;
      for (Object e : elements) {
        array[i++] = (Long) e;
      }
      return create(array);
    }

    /**
     * Creates a new collection containing the given elements; implement this method instead of
     * {@link #create(Object...)}.
     */
    protected abstract List<Long> create(Long[] elements);

    @Override
    public Long[] createArray(int length) {

 * synchronization primitives. The strategies are all implemented as subtypes of AtomicHelper and
 * the strategy is selected in the static initializer of AggregateFutureState. This is convenient
 * and performant but introduces some testing difficulties. This test exercises the two fallback
 * strategies.
 *
 * <ul>
 *   <li>SafeAtomicHelper: uses Atomic FieldsUpdaters to implement synchronization

 * {@link ValueGraph}, and {@link Network}):
 *
 * <pre>{@code
 * someGraphAlgorithm(startNode, graph);
 * }</pre>
 *
 * This works because those types each implement {@code PredecessorsFunction}. It will also work
 * with any other implementation of this interface.
 *
 * <p>If you have your own graph implementation based around a custom node type {@code MyNode},