* implementations. As a result, we need to make sure our TypeVariable implementation respects
   * symmetry. Moreover, we don't want to reconstruct a native type variable {@code <A>} using our
   * implementation unless some of its bounds have changed in resolution. This avoids creating
   * unequal TypeVariable implementation unnecessarily. When the bounds do change, however, it's

 *
 * <p>This uses the same efficient implementation as {@link Ordering#leastOf(Iterable, int)},
 * offering expected O(n + k log k) performance (worst case O(n log k)) for n calls to {@link
 * #offer} and a call to {@link #topK}, with O(k) memory. In comparison, quickselect has the same
 * asymptotics but requires O(n) memory, and a {@code PriorityQueue} implementation takes O(n log

   * implementations. As a result, we need to make sure our TypeVariable implementation respects
   * symmetry. Moreover, we don't want to reconstruct a native type variable {@code <A>} using our
   * implementation unless some of its bounds have changed in resolution. This avoids creating
   * unequal TypeVariable implementation unnecessarily. When the bounds do change, however, it's

         * TypeVariable implementation. This is a problem because users compare TypeVariables from
         * the JDK against TypeVariables returned by TypeResolver. To work with all JDK versions,
         * TypeResolver must return the appropriate TypeVariable implementation in each of the three
         * possible cases:
         *

         * TypeVariable implementation. This is a problem because users compare TypeVariables from
         * the JDK against TypeVariables returned by TypeResolver. To work with all JDK versions,
         * TypeResolver must return the appropriate TypeVariable implementation in each of the three
         * possible cases:
         *

import java.util.AbstractList;
import java.util.List;
import java.util.ListIterator;
import java.util.RandomAccess;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Lists#cartesianProduct(List)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class CartesianList<E> extends AbstractList<List<E>> implements RandomAccess {

- **Switch Expressions** - Optimized implementations using switch expressions for better performance
- **Sequenced Collections** - Full support for Java 21 sequenced collections API with dedicated utility methods
- **Performance Focused** - Optimized implementations for better runtime performance with reduced memory allocation

    /*
     * We'd use assertThrows here, but that causes no exception to be thrown under Java 8,
     * presumably because the ThrowingRunnable lambda triggers some kind of bug in Java 8's
     * reflection implementation.
     */
    try {
      new TypeToken<T>() {};
      fail();
    } catch (IllegalStateException expected) {
      // Type variables aren't allowed.
    }
  }

  public void testRawTypeIsCorrect() {

    /*
     * We'd use assertThrows here, but that causes no exception to be thrown under Java 8,
     * presumably because the ThrowingRunnable lambda triggers some kind of bug in Java 8's
     * reflection implementation.
     */
    try {
      new TypeToken<T>() {};
      fail();
    } catch (IllegalStateException expected) {
      // Type variables aren't allowed.
    }
  }

  public void testRawTypeIsCorrect() {

import java.util.Vector;
import java.util.concurrent.CopyOnWriteArrayList;
import junit.framework.Test;
import junit.framework.TestSuite;

/**
 * Generates a test suite covering the {@link List} implementations in the {@link java.util}
 * package. Can be subclassed to specify tests that should be suppressed.
 *
 * @author Kevin Bourrillion
 */
@GwtIncompatible
public class TestsForListsInJavaUtil {