* swapping them.
   *
   * <p>An empty iterable has only one permutation, which is an empty list.
   *
   * @param elements the original iterable whose elements have to be permuted.
   * @param comparator a comparator for the iterable's elements.
   * @return an immutable {@link Collection} containing all the different permutations of the
   *     original iterable.

import static java.util.concurrent.TimeUnit.SECONDS;

import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;

import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.mock;

import com.google.common.base.Function;
import com.google.common.collect.ForwardingObject;
import com.google.common.collect.Iterables;
import com.google.common.testing.ForwardingWrapperTester;
import java.lang.reflect.Method;
import java.util.Arrays;

/**
 * Tester for typical subclass of {@link ForwardingObject} by using Mockito.
 *

     *
     * @param <E>
     *            要素の型
     * @param iterables
     *            {@link Iterable}の並び。{@literal null}であってはいけません
     * @return {@link MultiIterator}をラップした{@link Iterable}
     */
    public static <E> Iterable<E> iterable(final Iterable<E>... iterables) {
        assertArgumentNotNull("iterables", iterables);

        @SuppressWarnings("unchecked")

   * they are returned by the iterable's iterator.
   *
   * @since 12.0
   */
  public static <E> ArrayDeque<E> newArrayDeque(Iterable<? extends E> elements) {
    if (elements instanceof Collection) {
      return new ArrayDeque<>((Collection<? extends E>) elements);
    }
    ArrayDeque<E> deque = new ArrayDeque<>();
    Iterables.addAll(deque, elements);
    return deque;

   * they are returned by the iterable's iterator.
   *
   * @since 12.0
   */
  public static <E> ArrayDeque<E> newArrayDeque(Iterable<? extends E> elements) {
    if (elements instanceof Collection) {
      return new ArrayDeque<>((Collection<? extends E>) elements);
    }
    ArrayDeque<E> deque = new ArrayDeque<>();
    Iterables.addAll(deque, elements);
    return deque;

  static <E> ImmutableSet<E> asImmutable(Set<E> delegate) {
    switch (delegate.size()) {
      case 0:
        return ImmutableSet.of();
      case 1:
        return ImmutableSet.of(Iterables.getOnlyElement(delegate));
      default:
        return new ImmutableEnumSet<E>(delegate);
    }
  }

  public ImmutableEnumSet(Set<E> delegate) {
    super(delegate);
  }

   * swapping them.
   *
   * <p>An empty iterable has only one permutation, which is an empty list.
   *
   * @param elements the original iterable whose elements have to be permuted.
   * @param comparator a comparator for the iterable's elements.
   * @return an immutable {@link Collection} containing all the different permutations of the
   *     original iterable.

  int charSplitter(int reps) {
    int total = 0;

    for (int i = 0; i < reps; i++) {
      total += Iterables.size(CHAR_SPLITTER.split(input));
    }

    return total;
  }

  @Benchmark
  int stringSplitter(int reps) {
    int total = 0;

    for (int i = 0; i < reps; i++) {
      total += Iterables.size(STRING_SPLITTER.split(input));
    }

    return total;
  }

  public boolean removeAll(Collection<?> c) {
    return Iterables.removeIf(
        multimap.unfiltered().entries(),
        // explicit <Entry<K, V>> is required to build with JDK6
        Predicates.<Entry<K, V>>and(
            multimap.entryPredicate(), Maps.<V>valuePredicateOnEntries(Predicates.in(c))));
  }

  @Override
  public boolean retainAll(Collection<?> c) {
    return Iterables.removeIf(
        multimap.unfiltered().entries(),