.expireAfterAccess(500000, TimeUnit.MILLISECONDS)
            .maximumSize(count)
            .build();
  }

  public void testComputeIfAbsent() {
    // simultaneous insertion for same key, expect 1 winner
    doParallelCacheOp(
        count,
        n -> {
          cache.asMap().computeIfAbsent(key, k -> "value" + n);
        });
    assertEquals(1, cache.size());
  }

            !item.equals(item.toString()));
      }
    }
  }

  /**
   * Class used to test whether equals() correctly handles an instance of an incompatible class.
   * Since it is a private inner class, the invoker can never pass in an instance to the tester
   */
  private enum NotAnInstance {
    EQUAL_TO_NOTHING;
  }

   * c, d, e]} with a partition size of 3 yields {@code [[a, b, c], [d, e]]} -- an outer list
   * containing two inner lists of three and two elements, all in the original order.
   *
   * <p>The outer list is unmodifiable, but reflects the latest state of the source list. The inner
   * lists are sublist views of the original list, produced on demand using {@link List#subList(int,

 * backing collection and the mutex are serializable.
 *
 * <p>If {@code null} is passed as the {@code mutex} parameter to any of this class's top-level
 * methods or inner class constructors, the created object uses itself as the synchronization mutex.
 *
 * <p>This class should be used by other collection classes only.
 *
 * @author Mike Bostock
 * @author Jared Levy
 */

      fail();
    } catch (CancellationException expected) {
      // There should be two CancellationException chained together.  The outer one should have the
      // stack trace of where the get() call was made, and the inner should have the stack trace of
      // where the immediateCancelledFuture() call was made.
      List<StackTraceElement> stackTrace = ImmutableList.copyOf(expected.getStackTrace());

      }
    }
  }

  @SuppressWarnings("unchecked")
  final Segment<K, V>[] newSegmentArray(int ssize) {
    return (Segment<K, V>[]) new Segment<?, ?>[ssize];
  }

  // Inner Classes

  /**
   * Segments are specialized versions of hash tables. This subclass inherits from ReentrantLock
   * opportunistically, just to simplify some locking and avoid separate construction.
   */

            new TestStringSetGenerator() {
              @Override
              protected Set<String> create(String[] elements) {
                TestSet<String> inner = new TestSet<>(new HashSet<String>(), null);
                Set<String> outer = Synchronized.set(inner, null);
                inner.mutex = outer;
                Collections.addAll(outer, elements);
                return outer;
              }
            })

    @SuppressWarnings("unchecked")
    NavigableMap<K, V> innermost =
        new SafeTreeMap<>((Comparator<? super K>) Ordering.natural().nullsFirst());
    TestMap<K, V> inner = new TestMap<>(innermost, mutex);
    NavigableMap<K, V> outer = Synchronized.navigableMap(inner, mutex);
    return outer;
  }

  static class TestEntry<K, V> extends ForwardingMapEntry<K, V> implements Serializable {
    private final Entry<K, V> delegate;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.graph.GraphConstants.INNER_CAPACITY;
import static com.google.common.graph.GraphConstants.INNER_LOAD_FACTOR;
import static com.google.common.graph.Graphs.checkNonNegative;
import static com.google.common.graph.Graphs.checkPositive;

import com.google.common.base.Function;

            .createTestSuite());
    return suite;
  }

  @Override
  protected <K, V> BiMap<K, V> create() {
    TestBiMap<K, V> inner = new TestBiMap<>(HashBiMap.<K, V>create(), mutex);
    BiMap<K, V> outer = Synchronized.biMap(inner, mutex);
    return outer;
  }

  public static final class SynchronizedHashBiMapGenerator extends TestStringBiMapGenerator {
    @Override