@GwtCompatible
@ElementTypesAreNonnullByDefault
final class Absent<T> extends Optional<T> {
  static final Absent<Object> INSTANCE = new Absent<>();

  @SuppressWarnings("unchecked") // implementation is "fully variant"
  static <T> Optional<T> withType() {
    return (Optional<T>) INSTANCE;
  }

  private Absent() {}

  @Override
  public boolean isPresent() {
    return false;
  }

  @Override

    super(message);
  }

  /**
   * Creates a new instance with the given detail message and cause. Prefer to provide a
   * non-nullable {@code cause}, as many users expect to find one.
   */
  public ExecutionError(@CheckForNull String message, @CheckForNull Error cause) {
    super(message, cause);
  }

  /**
   * Creates a new instance with {@code null} as its detail message and the given cause. Prefer to

/**
 * A simple {@link Supplier} of {@link SessionBuilder} instances, that on each call supplies newly
 * constructed instance. To create session out of builder, use {@link SessionBuilder#build()}. For proper closing
 * of sessions, use {@link CloseableSession#close()} method on built instance(s).
 * <p>
 * Extend this class and override methods to customize, if needed.
 *
 * @since 4.0.0

      if (Serializable.class.isAssignableFrom(classToTest)) {
        try {
          Object instance = tester.instantiate(classToTest);
          if (instance != null) {
            if (isEqualsDefined(classToTest)) {
              SerializableTester.reserializeAndAssert(instance);
            } else {
              SerializableTester.reserialize(instance);
            }
          }
        } catch (Throwable e) {

    boolean matches(CtClass ctClass) {
        return KotlinMetadataQueries.INSTANCE.isKotlinInternal(ctClass)
    }

    @Override
    boolean matches(CtField ctField) {
        return KotlinMetadataQueries.INSTANCE.isKotlinInternal(ctField)
    }

    @Override
    boolean matches(CtBehavior ctBehavior) {
        return KotlinMetadataQueries.INSTANCE.isKotlinInternal(ctBehavior)
    }

  }

  private static GetCheckedTypeValidator nonCachingWithoutConstructorCheckValidator() {
    return NonCachingWithoutConstructorCheckValidator.INSTANCE;
  }

  private enum NonCachingWithoutConstructorCheckValidator implements GetCheckedTypeValidator {
    INSTANCE;

    @Override
    public void validateClass(Class<? extends Exception> exceptionClass) {
      checkArgument(

The build tree state is managed by the `BuildTreeState` class.
An instance is created at the start of a build execution and discarded at the end of the execution.

### Build state

The "build state" holds the state for a build within the build definition for a single build execution, and is contained by the build tree state.

The build state is managed by the `BuildState` class.

  }

  @Override
  public <S extends Comparable<?>> Ordering<S> reverse() {
    return (Ordering<S>) ReverseNaturalOrdering.INSTANCE;
  }

  // preserving singleton-ness gives equals()/hashCode() for free
  private Object readResolve() {
    return INSTANCE;
  }

  @Override
  public String toString() {
    return "Ordering.natural()";
  }

  private NaturalOrdering() {}

      return INSTANCE;
    }

    private static final long serialVersionUID = 0;
  }

  /*
   * The implementation neither produces nor consumes any non-null instance of
   * type C, so casting the type parameter is safe.
   */
  @SuppressWarnings("unchecked")
  static <C extends Comparable> Cut<C> aboveAll() {
    return (Cut<C>) AboveAll.INSTANCE;
  }

/**
 * A simple memorizing {@link Supplier} of {@link RepositorySystem} instance, that on first call
 * supplies lazily constructed instance, and on each subsequent call same instance. Hence, this instance should be
 * thrown away immediately once repository system was created and there is no need for more instances. If new
 * repository system instance needed, new instance of this class must be created. For proper shut down of returned