assertThat(DoubleMath.mean(ImmutableList.of(11, -22, 44, -88).iterator()))
        .isWithin(1.0e-10)
        .of(-13.75);
    assertThat(DoubleMath.mean(ImmutableList.of(11).iterator())).isWithin(1.0e-10).of(11);
    assertThrows(
        IllegalArgumentException.class,
        () -> DoubleMath.mean(ImmutableList.<Integer>of().iterator()));
  }

  @GwtIncompatible // DoubleMath.mean

            return parent.isEmpty();
        }

        public boolean contains(final Object o) {
            return parent.contains(o);
        }

        public Iterator<E> iterator() {
            return parent.iterator();
        }

        public Object[] toArray() {
            return parent.toArray();
        }

        public <T> T[] toArray(final T[] a) {

        return new AbstractSet<>() {
            @Override
            public Iterator<Entry<String, String>> iterator() {
                return new Iterator<>() {
                    final Iterator<Entry<String, String>> keyIterator =
                            storage.entrySet().iterator();

                    @Override
                    public boolean hasNext() {

        return new AbstractSet<>() {
            @Override
            public Iterator<Entry<String, String>> iterator() {
                return new Iterator<>() {
                    final Iterator<Entry<String, String>> keyIterator =
                            storage.entrySet().iterator();

                    @Override
                    public boolean hasNext() {

  ImmutableMapKeySet(ImmutableMap<K, V> map) {
    this.map = map;
  }

  @Override
  public int size() {
    return map.size();
  }

  @Override
  public UnmodifiableIterator<K> iterator() {
    return map.keyIterator();
  }

  @Override
  public boolean contains(@Nullable Object object) {
    return map.containsKey(object);
  }

  @Override
  K get(int index) {

 */

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;

/**
 * A generator that relies on a preexisting generator for most of its work. For example, a derived
 * iterator generator may delegate the work of creating the underlying collection to an inner
 * collection generator.
 *
 * <p>{@code GwtTestSuiteGenerator} expects every {@code DerivedIterator} implementation to provide

 */

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;

/**
 * A generator that relies on a preexisting generator for most of its work. For example, a derived
 * iterator generator may delegate the work of creating the underlying collection to an inner
 * collection generator.
 *
 * <p>{@code GwtTestSuiteGenerator} expects every {@code DerivedIterator} implementation to provide

    @Override
    public Set<Map.Entry<K, V>> entrySet() {
        if (entrySet == null) {
            entrySet = new AbstractSet<Entry<K, V>>() {
                @Override
                public Iterator<Entry<K, V>> iterator() {
                    return new ArrayMapIterator();
                }

                @Override
                public boolean contains(final Object o) {

   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(Collection<T> collection) {
    // return collection::iterator;
    return new Iterable<T>() {
      @Override
      public Iterator<T> iterator() {
        return collection.iterator();
      }
    };
  }

  public void testEquals() {
    new EqualsTester()
        .addEqualityGroup(ImmutableLongArray.of())

      for (List<Integer> contents : SAMPLE_INPUTS) {
        C unfiltered = createUnfiltered(contents);
        C filtered = filter(unfiltered, EVEN);

        Iterator<Integer> filteredItr = filtered.iterator();
        for (Integer i : unfiltered) {
          if (EVEN.apply(i)) {
            assertTrue(filteredItr.hasNext());
            assertEquals(i, filteredItr.next());
          }
        }