.build();

  /**
   * type → implementation. Inherently mutable interfaces and abstract classes are mapped to their
   * default implementations and are "new"d upon get().
   */
  private static final ConcurrentMap<Class<?>, Class<?>> implementations = Maps.newConcurrentMap();

  private static <T> void setImplementation(Class<T> type, Class<? extends T> implementation) {

import java.util.Collections;
import java.util.Iterator;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A utility for testing an Iterator implementation by comparing its behavior to that of a "known
 * good" reference implementation. In order to accomplish this, it's important to test a great
 * variety of sequences of the {@link Iterator#next}, {@link Iterator#hasNext} and {@link

import com.google.common.annotations.GwtIncompatible;
import java.util.List;

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests a
 * ConcurrentNavigableMap implementation.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible
public class ConcurrentNavigableMapTestSuiteBuilder<K, V>
    extends NavigableMapTestSuiteBuilder<K, V> {

import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Iterator;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An implementation of {@code Iterable} which throws an exception on all invocations of the {@link
 * #iterator()} method after the first, and whose iterator is always unmodifiable.
 *

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.ArrayList;
import java.util.List;

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests a queue
 * implementation.
 *
 * @author Jared Levy
 */
@GwtIncompatible
public final class QueueTestSuiteBuilder<E>
    extends AbstractCollectionTestSuiteBuilder<QueueTestSuiteBuilder<E>, E> {

import java.util.HashSet;
import java.util.List;
import java.util.Set;
import junit.framework.TestSuite;

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests a Set implementation.
 *
 * @author George van den Driessche
 */
@GwtIncompatible
public class SetTestSuiteBuilder<E>
    extends AbstractCollectionTestSuiteBuilder<SetTestSuiteBuilder<E>, E> {

import java.util.NavigableSet;
import java.util.Set;
import java.util.SortedSet;
import junit.framework.TestSuite;

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests a NavigableSet
 * implementation.
 */
@GwtIncompatible
public final class NavigableSetTestSuiteBuilder<E> extends SortedSetTestSuiteBuilder<E> {
  public static <E> NavigableSetTestSuiteBuilder<E> using(TestSortedSetGenerator<E> generator) {

    int size = getNumElements();

    assertThrows(
        NullPointerException.class, () -> multimap().putAll(k3(), Lists.newArrayList(null, v3())));

    /*
     * In principle, a Multimap implementation could add e3 first before failing on the null. But
     * that seems unlikely enough to be worth complicating the test over, especially if there's any
     * chance that a permissive test could mask a bug.
     */

  /**
   * Prevents the given methods from being run as part of the test suite.
   *
   * <p>Note: in principle this should never need to be used, but it might be useful if the
   * semantics of an implementation disagree in unforeseen ways with the semantics expected by a
   * test, or to keep dependent builds clean in spite of an erroneous test.
   */
  @CanIgnoreReturnValue
  public B suppressing(Method... methods) {

  }

  /**
   * Serialized type for all ImmutableSortedMap instances. It captures the logical contents and they
   * are reconstructed using public factory methods. This ensures that the implementation types
   * remain as implementation details.
   */
  @J2ktIncompatible // serialization
  private static class SerializedForm<K, V> extends ImmutableMap.SerializedForm<K, V> {
    private final Comparator<? super K> comparator;