import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.time.Duration;
import java.util.Objects;
import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.Nullable;

/**
 * Useful suppliers.
 *
 * <p>All methods return serializable suppliers as long as they're given serializable parameters.
 *
 * @author Laurence Gonsalves
 * @author Harry Heymann
 * @since 2.0

    }
    assertFalse(errorNotThrown);
  }

  private static class ClassWhichDoesNotImplementEquals implements Serializable {
    private static final long serialVersionUID = 1L;
  }

  private static class ClassWhichIsAlwaysEqualButHasDifferentHashcodes implements Serializable {
    private static final long serialVersionUID = 2L;

    @SuppressWarnings("EqualsHashCode")
    @Override

    }
    assertFalse(errorNotThrown);
  }

  private static class ClassWhichDoesNotImplementEquals implements Serializable {
    private static final long serialVersionUID = 1L;
  }

  private static class ClassWhichIsAlwaysEqualButHasDifferentHashcodes implements Serializable {
    private static final long serialVersionUID = 2L;

    @SuppressWarnings("EqualsHashCode")
    @Override

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.time.Duration;
import java.util.Objects;
import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.Nullable;

/**
 * Useful suppliers.
 *
 * <p>All methods return serializable suppliers as long as they're given serializable parameters.
 *
 * @author Laurence Gonsalves
 * @author Harry Heymann
 * @since 2.0

            .named("ImmutableList")
            .withFeatures(CollectionSize.ANY, SERIALIZABLE, ALLOWS_NULL_QUERIES)
            .createTestSuite());
    suite.addTest(
        ListTestSuiteBuilder.using(new BuilderAddAllListGenerator())
            .named("ImmutableList, built with Builder.add")
            .withFeatures(CollectionSize.ANY, SERIALIZABLE, ALLOWS_NULL_QUERIES)
            .createTestSuite());
    suite.addTest(

   * covered.
   */
  protected final void publicApiOnly() {
    visibility = Visibility.PUBLIC;
  }

  /**
   * Tests all top-level {@link Serializable} classes in the package. For a serializable Class
   * {@code C}:
   *
   * <ul>
   *   <li>If {@code C} explicitly implements {@link Object#equals}, the deserialized instance will

   * covered.
   */
  protected final void publicApiOnly() {
    visibility = Visibility.PUBLIC;
  }

  /**
   * Tests all top-level {@link Serializable} classes in the package. For a serializable Class
   * {@code C}:
   *
   * <ul>
   *   <li>If {@code C} explicitly implements {@link Object#equals}, the deserialized instance will

            .named("ImmutableList")
            .withFeatures(CollectionSize.ANY, SERIALIZABLE, ALLOWS_NULL_QUERIES)
            .createTestSuite());
    suite.addTest(
        ListTestSuiteBuilder.using(new BuilderAddAllListGenerator())
            .named("ImmutableList, built with Builder.add")
            .withFeatures(CollectionSize.ANY, SERIALIZABLE, ALLOWS_NULL_QUERIES)
            .createTestSuite());
    suite.addTest(

        // The presence of serialVersionUID is verified at compile time
        // and the exception extends RuntimeException which is Serializable
        assertTrue(exception instanceof java.io.Serializable);
    }

    @Test
    public void test_toString() {
        // Test toString method
        String message = "Test exception message";

  }

  private static final class ContainsMultiset implements Serializable {
    private final ConcurrentHashMultiset<?> multiset;

    ContainsMultiset(ConcurrentHashMultiset<?> multiset) {
      this.multiset = multiset;
    }
  }

  private static final class ContainsBothWithMultisetFirst implements Serializable {
    private final ConcurrentHashMultiset<?> a;
    private final ContainsMultiset z;