* signal the first active guard that is satisfied. But the corresponding thread may have already
   * been interrupted and is waiting to reacquire the lock while still registered in activeGuards,
   * in which case the signal is a no-op, and the bigger-picture signal is lost unless interrupted
   * threads take special action by participating in the signal-passing game.
   */

  /*

      public int size() {
        return rest.length + 2;
      }

      @Override
      @CheckForNull
      public Object get(int index) {
        switch (index) {
          case 0:
            return first;
          case 1:
            return second;
          default:
            return rest[index - 2];
        }
      }
    };
  }

     *
     * <p>When this method returns, the {@code acquiredLock} should be in either the {@code
     * preAcquireLocks} map, for the case in which it is safe to acquire {@code this} after the
     * {@code acquiredLock}, or in the {@code disallowedPriorLocks} map, in which case it is not
     * safe.
     */
    void checkAcquiredLock(Policy policy, LockGraphNode acquiredLock) {

 * <b>indiscriminately</b> to the methods of the delegate. For example, overriding {@link
 * #add(Object, int)} alone <b>will not</b> change the behavior of {@link #add(Object)}, which can
 * lead to unexpected behavior. In this case, you should override {@code add(Object)} as well,
 * either providing your own implementation, or delegating to the provided {@code standardAdd}
 * method.
 *

    }

    /**
     * The number of permutations with repeated elements is calculated as follows:
     *
     * <ul>
     *   <li>For an empty list, it is 1 (base case).
     *   <li>When r numbers are added to a list of n-r elements, the number of permutations is
     *       increased by a factor of (n choose r).
     * </ul>
     */
    private static <E> int calculateSize(

    FluentIterable<? extends Number> numbers = getSomeNumbers();

    // Sadly, the following is what users will have to do in some circumstances.

    @SuppressWarnings("unchecked") // safe covariant cast
    Optional<Number> first = (Optional<Number>) numbers.first();
    Number value = first.or(0.5); // fine
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullPointers() {

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicInteger;
import junit.framework.TestCase;

/**
 * Test case for {@link EventBus}.
 *
 * @author Cliff Biffle
 */
public class EventBusTest extends TestCase {
  private static final String EVENT = "Hello";
  private static final String BUS_IDENTIFIER = "test-bus";

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicInteger;
import junit.framework.TestCase;

/**
 * Test case for {@link EventBus}.
 *
 * @author Cliff Biffle
 */
public class EventBusTest extends TestCase {
  private static final String EVENT = "Hello";
  private static final String BUS_IDENTIFIER = "test-bus";

      Multiset<? extends E> multiset) {
    if (multiset instanceof UnmodifiableMultiset || multiset instanceof ImmutableMultiset) {
      @SuppressWarnings("unchecked") // Since it's unmodifiable, the covariant cast is safe
      Multiset<E> result = (Multiset<E>) multiset;
      return result;
    }
    return new UnmodifiableMultiset<>(checkNotNull(multiset));
  }

  /**
   * Simply returns its argument.
   *

  }

  public void testToImmutableSortedMap() {
    Collector<Entry<String, Integer>, ?, ImmutableSortedMap<String, Integer>> collector =
        ImmutableSortedMap.toImmutableSortedMap(
            String.CASE_INSENSITIVE_ORDER, Entry::getKey, Entry::getValue);
    BiPredicate<ImmutableSortedMap<String, Integer>, ImmutableSortedMap<String, Integer>>
        equivalence =
            Equivalence.equals()