for (ListTestSuiteBuilder<Integer> builder : builders) {
      suite.addTest(
          builder
              .withFeatures(
                  CollectionSize.ONE,
                  CollectionSize.SEVERAL,
                  CollectionFeature.RESTRICTS_ELEMENTS,
                  ListFeature.SUPPORTS_SET)
              .createTestSuite());
    }
    return suite;
  }

   */
  @SuppressWarnings("unchecked")
  public static <T extends @Nullable Object> Collector<T, ?, T> onlyElement() {
    return (Collector) ONLY_ELEMENT;
  }

  /**
   * This atrocity is here to let us report several of the elements in the stream if there were more
   * than one, not just two.
   */
  @SuppressWarnings("EmptyList") // ImmutableList doesn't support nullable element types
  private static final class ToOptionalState {

   */
  @SuppressWarnings("unchecked")
  public static <T extends @Nullable Object> Collector<T, ?, T> onlyElement() {
    return (Collector) ONLY_ELEMENT;
  }

  /**
   * This atrocity is here to let us report several of the elements in the stream if there were more
   * than one, not just two.
   */
  @SuppressWarnings("EmptyList") // ImmutableList doesn't support nullable element types
  private static final class ToOptionalState {

              }
            })
        .named("badly colliding HashSet")
        .withFeatures(
            SetFeature.GENERAL_PURPOSE,
            CollectionFeature.ALLOWS_NULL_VALUES,
            CollectionSize.SEVERAL)
        .suppressing(suppressForHashSet())
        .createTestSuite();
  }

  public Test testsForConcurrentSkipListSetNatural() {
    return SetTestSuiteBuilder.using(

import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Helper class for creating {@link CacheBuilder} instances with all combinations of several sets of
 * parameters.
 *
 * @author mike nonemacher
 */
@NullUnmarked
class CacheBuilderFactory {
  // Default values contain only 'null', which means don't call the CacheBuilder method (just give

              }
            })
        .named("badly colliding HashSet")
        .withFeatures(
            SetFeature.GENERAL_PURPOSE,
            CollectionFeature.ALLOWS_NULL_VALUES,
            CollectionSize.SEVERAL)
        .suppressing(suppressForHashSet())
        .createTestSuite();
  }

  public Test testsForConcurrentSkipListSetNatural() {
    return SetTestSuiteBuilder.using(

   * note that the execution order of all listeners is ultimately chosen by the implementations of
   * the supplied executors.
   *
   * <p>This method is idempotent. Calling it several times in parallel is semantically equivalent
   * to calling it exactly once.
   *
   * @since 10.0 (present in 1.0 as {@code run})
   */
  public void execute() {

   * note that the execution order of all listeners is ultimately chosen by the implementations of
   * the supplied executors.
   *
   * <p>This method is idempotent. Calling it several times in parallel is semantically equivalent
   * to calling it exactly once.
   *
   * @since 10.0 (present in 1.0 as {@code run})
   */
  public void execute() {

 * may never contain more than {@link Integer#MAX_VALUE} occurrences of any one element.
 *
 * <p>{@code Multiset} refines the specifications of several methods from {@code Collection}. It
 * also defines an additional query operation, {@link #count}, which returns the count of an
 * element. There are five new bulk-modification operations, for example {@link #add(Object, int)},

 * may never contain more than {@link Integer#MAX_VALUE} occurrences of any one element.
 *
 * <p>{@code Multiset} refines the specifications of several methods from {@code Collection}. It
 * also defines an additional query operation, {@link #count}, which returns the count of an
 * element. There are five new bulk-modification operations, for example {@link #add(Object, int)},