* limitations under the License.
 */

package com.google.common.collect.testing.features;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.Helpers;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Set;

      Iterable<? extends ListenableFuture<? extends V>> futures) {
    return new FutureCombiner<>(true, ImmutableList.copyOf(futures));
  }

  /**
   * A helper to create a new {@code ListenableFuture} whose result is generated from a combination
   * of input futures.
   *
   * <p>See {@link #whenAllComplete} and {@link #whenAllSucceed} for how to instantiate this class.
   *

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing;

import static com.google.common.collect.testing.Helpers.castOrCopyToList;
import static java.util.Collections.reverse;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.testing.DerivedCollectionGenerators.Bound;

    ImmutableMap.Builder<String, Integer> builder = new Builder<>();
    final StringHolder holder = new StringHolder();
    holder.string = "one";
    Entry<String, Integer> entry =
        new AbstractMapEntry<String, Integer>() {
          @Override
          public String getKey() {
            return holder.string;
          }

          @Override
          public Integer getValue() {

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Converter;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.testing.Helpers;
import com.google.common.testing.NullPointerTester;
import com.google.common.testing.SerializableTester;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Converter;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.testing.Helpers;
import com.google.common.testing.NullPointerTester;
import com.google.common.testing.SerializableTester;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;

   *
   * @since 21.0
   */
  public java.util.Optional<T> toJavaUtil() {
    return java.util.Optional.ofNullable(orNull());
  }

  Optional() {}

  /**
   * Returns {@code true} if this holder contains a (non-null) instance.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> no differences.
   */
  public abstract boolean isPresent();

  /**

import static com.google.common.collect.Maps.transformValues;
import static com.google.common.collect.Maps.unmodifiableNavigableMap;
import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.truth.Truth.assertThat;
import static com.google.common.truth.Truth.assertWithMessage;
import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;

import static com.google.common.collect.Maps.transformValues;
import static com.google.common.collect.Maps.unmodifiableNavigableMap;
import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.truth.Truth.assertThat;
import static com.google.common.truth.Truth.assertWithMessage;
import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;

  @Override
  public SampleElements<Entry<String, String>> samples() {
    return new SampleElements<>(
        Helpers.mapEntry("one", "January"),
        Helpers.mapEntry("two", "February"),
        Helpers.mapEntry("three", "March"),
        Helpers.mapEntry("four", "April"),
        Helpers.mapEntry("five", "May"));
  }

  @Override
  public SampleElements<String> sampleKeys() {