* "https://github.com/google/guava/wiki/RangesExplained#discrete-domains">{@code
 * DiscreteDomain}</a>.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
@GwtCompatible
public abstract class DiscreteDomain<C extends Comparable> {

  /**
   * Returns the discrete domain for values of type {@code Integer}.
   *

 * "https://github.com/google/guava/wiki/RangesExplained#discrete-domains">{@code
 * DiscreteDomain}</a>.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
@GwtCompatible
public abstract class DiscreteDomain<C extends Comparable> {

  /**
   * Returns the discrete domain for values of type {@code Integer}.
   *

  abstract Cut<C> withUpperBoundType(BoundType boundType, DiscreteDomain<C> domain);

  abstract void describeAsLowerBound(StringBuilder sb);

  abstract void describeAsUpperBound(StringBuilder sb);

  abstract @Nullable C leastValueAbove(DiscreteDomain<C> domain);

  abstract @Nullable C greatestValueBelow(DiscreteDomain<C> domain);

  /*

    return 0;
  }

  @GwtIncompatible
  @J2ktIncompatible
  private static final class SerializedForm<C extends Comparable> implements Serializable {
    private final DiscreteDomain<C> domain;

    private SerializedForm(DiscreteDomain<C> domain) {
      this.domain = domain;
    }

    private Object readResolve() {
      return new EmptyContiguousSet<>(domain);
    }

  abstract Cut<C> withUpperBoundType(BoundType boundType, DiscreteDomain<C> domain);

  abstract void describeAsLowerBound(StringBuilder sb);

  abstract void describeAsUpperBound(StringBuilder sb);

  abstract @Nullable C leastValueAbove(DiscreteDomain<C> domain);

  abstract @Nullable C greatestValueBelow(DiscreteDomain<C> domain);

  /*

/**
 * Tests for {@link DiscreteDomain}.
 *
 * @author Chris Povirk
 */
@GwtIncompatible // SerializableTester
@NullUnmarked
public class DiscreteDomainTest extends TestCase {
  public void testSerialization() {
    reserializeAndAssert(DiscreteDomain.integers());
    reserializeAndAssert(DiscreteDomain.longs());
    reserializeAndAssert(DiscreteDomain.bigIntegers());
  }

   * @since 23.0
   */
  public static ContiguousSet<Long> closedOpen(long lower, long upper) {
    return create(Range.closedOpen(lower, upper), DiscreteDomain.longs());
  }

  final DiscreteDomain<C> domain;

  ContiguousSet(DiscreteDomain<C> domain) {
    super(Ordering.natural());
    this.domain = domain;
  }

  @Override
  public ContiguousSet<C> headSet(C toElement) {

    return 0;
  }

  @GwtIncompatible
  @J2ktIncompatible
  private static final class SerializedForm<C extends Comparable> implements Serializable {
    private final DiscreteDomain<C> domain;

    private SerializedForm(DiscreteDomain<C> domain) {
      this.domain = domain;
    }

    private Object readResolve() {
      return new EmptyContiguousSet<>(domain);
    }

   * @since 23.0
   */
  public static ContiguousSet<Long> closedOpen(long lower, long upper) {
    return create(Range.closedOpen(lower, upper), DiscreteDomain.longs());
  }

  final DiscreteDomain<C> domain;

  ContiguousSet(DiscreteDomain<C> domain) {
    super(Ordering.natural());
    this.domain = domain;
  }

  @Override
  public ContiguousSet<C> headSet(C toElement) {

      throw new IllegalArgumentException(
          "Neither the DiscreteDomain nor this range set are bounded below");
    } else if (!span.hasUpperBound()) {
      try {
        domain.maxValue();
      } catch (NoSuchElementException e) {
        throw new IllegalArgumentException(
            "Neither the DiscreteDomain nor this range set are bounded above");
      }
    }