@Override
  public boolean put(@ParametricNullness K key, @ParametricNullness V value) {
    return get(key).add(value);
  }

  @CanIgnoreReturnValue
  @Override
  public boolean putAll(@ParametricNullness K key, Iterable<? extends V> values) {
    checkNotNull(values);
    // make sure we only call values.iterator() once
    // and we only call get(key) if values is nonempty
    if (values instanceof Collection) {

  /**
   * Find all the tester annotations declared on a tester class or method.
   *
   * @param classOrMethod a class or method whose tester annotations to find
   * @return an iterable sequence of tester annotations on the class
   */
  public static Iterable<Annotation> getTesterAnnotations(AnnotatedElement classOrMethod) {
    synchronized (annotationCache) {
      List<Annotation> annotations = annotationCache.get(classOrMethod);

    }
  }

  /**
   * Returns a funnel that processes an {@code Iterable} by funneling its elements in iteration
   * order with the specified funnel. No separators are added between the elements.
   *
   * @since 15.0
   */
  public static <E extends @Nullable Object> Funnel<Iterable<? extends E>> sequentialFunnel(
      Funnel<E> elementFunnel) {
    return new SequentialFunnel<>(elementFunnel);

    SEQUENTIAL {
      @Override
      final <T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object>
          A result(Collector<T, A, R> collector, Iterable<T> inputs) {
        A accum = collector.supplier().get();
        for (T input : inputs) {
          collector.accumulator().accept(accum, input);
        }
        return accum;
      }
    },

    }
  }

  /**
   * Returns a funnel that processes an {@code Iterable} by funneling its elements in iteration
   * order with the specified funnel. No separators are added between the elements.
   *
   * @since 15.0
   */
  public static <E extends @Nullable Object> Funnel<Iterable<? extends E>> sequentialFunnel(
      Funnel<E> elementFunnel) {
    return new SequentialFunnel<>(elementFunnel);

 * Comparators#least(int)} to {@link Stream#collect(java.util.stream.Collector)}. If it is available
 * as an {@link Iterable} or {@link Iterator}, prefer {@link Ordering#leastOf(Iterable, int)}.
 *
 * <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

import com.google.common.collect.testing.features.MapFeature;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.junit.Ignore;

/**
 * Tests for {@link Multimap#replaceValues(Object, Iterable)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

      checkNotNull(elements); // for GWT
      for (E element : elements) {
        add(checkNotNull(element));
      }
      return this;
    }

    @CanIgnoreReturnValue
    public Builder<E> addAll(Iterable<? extends E> elements) {
      checkNotNull(elements); // for GWT
      for (E element : elements) {
        add(checkNotNull(element));
      }
      return this;
    }

    @CanIgnoreReturnValue

      return ((Multiset<E>) gen.create(duplicated)).elementSet();
    }

    @Override
    public E[] createArray(int length) {
      return gen.createArray(length);
    }

    @Override
    public Iterable<E> order(List<E> insertionOrder) {
      return gen.order(new ArrayList<E>(new LinkedHashSet<E>(insertionOrder)));
    }
  }

   */
  protected IteratorTester(
      int steps,
      Iterable<? extends IteratorFeature> features,
      Iterable<E> expectedElements,
      KnownOrder knownOrder) {
    super(steps, Collections.<E>singleton(null), features, expectedElements, knownOrder, 0);
  }

  @Override
  protected final Iterable<Stimulus<E, Iterator<E>>> getStimulusValues() {
    return iteratorStimuli();
  }