CURRENT = JAVA6;
      }
    }

    abstract Type newArrayType(Type componentType);

    abstract Type usedInGenericType(Type type);

    final ImmutableList<Type> usedInGenericType(Type[] types) {
      ImmutableList.Builder<Type> builder = ImmutableList.builder();
      for (Type type : types) {
        builder.add(usedInGenericType(type));
      }
      return builder.build();
    }

  }

  private static String paramString(Class<?> type, int i) {
    return type.getSimpleName() + '@' + i;
  }

  /**
   * Annotates a method to be the instance generator of a certain type. The return type is the
   * generated type. The method parameters correspond to the generated type's type parameters. For

    if (type.isArray()) {
      return createEmptyArray(type);
    }
    T jvmDefault = Defaults.defaultValue(Primitives.unwrap(type));
    if (jvmDefault != null) {
      return jvmDefault;
    }
    if (Modifier.isAbstract(type.getModifiers()) || !Modifier.isPublic(type.getModifiers())) {
      return arbitraryConstantInstanceOrNull(type);
    }
    final Constructor<T> constructor;
    try {

  private static <T> void setImplementation(Class<T> type, Class<? extends T> implementation) {
    checkArgument(type != implementation, "Don't register %s to itself!", type);
    checkArgument(
        !DEFAULTS.containsKey(type), "A default value was already registered for %s", type);
    checkArgument(
        implementations.put(type, implementation) == null,
        "Implementation for %s was already registered",

  /*
   * This class is used to serialize all ImmutableSortedSet instances,
   * regardless of implementation type. It captures their "logical contents"
   * only. This is necessary to ensure that the existence of a particular
   * implementation type is an implementation detail.
   */
  @J2ktIncompatible // serialization
  private static class SerializedForm<E> implements Serializable {

 * reference. It allows you to represent "a {@code T} that must be present" and a "a {@code T} that
 * might be absent" as two distinct types in your program, which can aid clarity.
 *
 * <p>Some uses of this class include
 *
 * <ul>
 *   <li>As a method return type, as an alternative to returning {@code null} to indicate that no
 *       value was available

   * given types. Otherwise, it will be rethrown wrapped in a {@code RuntimeException}. <b>Note:</b>
   * Be sure to declare all of the checked exception types your try block can throw when calling an
   * overload of this method so as to avoid losing the original exception type.
   *

   *
   * @param throwable the Throwable to possibly propagate
   * @param declaredType1 any checked exception type declared by the calling method
   * @param declaredType2 any other checked exception type declared by the calling method
   * @deprecated Use a combination of two calls to {@link #throwIfInstanceOf} and one call to {@link

   *
   * @param throwable the Throwable to possibly propagate
   * @param declaredType1 any checked exception type declared by the calling method
   * @param declaredType2 any other checked exception type declared by the calling method
   * @deprecated Use a combination of two calls to {@link #throwIfInstanceOf} and one call to {@link

  }

  private static String paramString(Class<?> type, int i) {
    return type.getSimpleName() + '@' + i;
  }

  /**
   * Annotates a method to be the instance generator of a certain type. The return type is the
   * generated type. The method parameters correspond to the generated type's type parameters. For