* implementations in Java use). For the many uses of hash functions beyond data structures,
 * however, {@code Object.hashCode} almost always falls short -- hence this library.
 *
 * @author Kevin Bourrillion
 * @since 11.0
 */
@Immutable
@ElementTypesAreNonnullByDefault
public interface HashFunction {
  /**

 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingMap}.
 *
 * <p>Each of the {@code standard} methods, where appropriate, use {@link Objects#equal} to test
 * equality for both keys and values. This may not be the desired behavior for map implementations

   * context class loader will find resources from the class path. In environments where different
   * threads can have different class loaders, for example app servers, the context class loader
   * will typically have been set to an appropriate loader for the current thread.
   *
   * <p>In the unusual case where the context class loader is null, the class loader that loaded

   *
   * @see java.util.Collection the definition of general-purpose collections.
   */
  GENERAL_PURPOSE(SUPPORTS_ADD, SUPPORTS_REMOVE, SUPPORTS_ITERATOR_REMOVE),

  /** Features supported by collections where only removal is allowed. */
  REMOVE_OPERATIONS(SUPPORTS_REMOVE, SUPPORTS_ITERATOR_REMOVE),

  SERIALIZABLE,
  SERIALIZABLE_INCLUDING_VIEWS(SERIALIZABLE),

  SUBSET_VIEW,
  DESCENDING_VIEW,

  /**

 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingCollection}.
 *
 * <p>The {@code standard} methods are not guaranteed to be thread-safe, even when all of the
 * methods that they depend on are thread-safe.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman

    // tells the computing thread when to start computing
    final CountDownLatch computeSignal = new CountDownLatch(1);
    // tells the main thread when computation is pending
    final CountDownLatch secondSignal = new CountDownLatch(1);
    // tells the main thread when the second get has started
    final CountDownLatch thirdSignal = new CountDownLatch(1);
    // tells the main thread when the third get has started

     */
    NEXT_HIGHER {
      @Override
      public int resultIndex(int higherIndex) {
        return higherIndex;
      }
    },
    /**
     * Return {@code ~insertionIndex}, where {@code insertionIndex} is defined as the point at which
     * the key would be inserted into the list: the index of the next higher element in the list, or
     * {@code list.size()} if there is no such element.
     *

    Type t = aTypeVariable();
    assertEquals(String.class, new TypeResolver().where(t, String.class).resolveType(t));
  }

  public <T> void testWhere_indirectMapping() {
    Type t1 = new TypeCapture<T>() {}.capture();
    Type t2 = aTypeVariable();
    assertEquals(
        String.class, new TypeResolver().where(t1, t2).where(t2, String.class).resolveType(t1));
  }

  public void testWhere_typeVariableSelfMapping() {

  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  private void appendUserObject(StringBuilder builder, @CheckForNull Object o) {
    // This is some basic recursion detection for when people create cycles via set/setFuture or
    // when deep chains of futures exist resulting in a StackOverflowException. We could detect
    // arbitrary cycles using a thread local but this should be a good enough solution (it is also

 * href="https://docs.oracle.com/javase/8/docs/technotes/guides/language/assert.html">assertions</a>,
 * except that they are always enabled. These methods should be used instead of Java assertions
 * whenever there is a chance the check may fail "in real life". Example:
 *
 * <pre>{@code
 * Bill bill = remoteService.getLastUnpaidBill();
 *
 * // In case bug 12345 happens again we'd rather just die