Set<Feature<?>> features = newHashSet(FOO);
    assertThat(addImpliedFeatures(features)).isSameInstanceAs(features);
  }

  public void testAddImpliedFeatures_addsImpliedFeatures() {
    assertThat(addImpliedFeatures(newHashSet(FOO))).containsExactly(FOO);

    assertThat(addImpliedFeatures(newHashSet(IMPLIES_IMPLIES_FOO)))
        .containsExactly(IMPLIES_IMPLIES_FOO, IMPLIES_FOO, FOO);

import static com.google.common.collect.testing.Helpers.copyToSet;
import static com.google.common.collect.testing.Helpers.getMethod;
import static com.google.common.collect.testing.features.FeatureUtil.addImpliedFeatures;
import static java.util.Arrays.asList;
import static java.util.Collections.disjoint;
import static java.util.Collections.unmodifiableSet;
import static java.util.logging.Level.FINER;

 */

package com.google.common.collect.testing;

import static com.google.common.collect.testing.Helpers.copyToSet;
import static com.google.common.collect.testing.features.FeatureUtil.addImpliedFeatures;
import static java.util.Arrays.asList;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.Feature;

   *
   * @param features the set of features to expand
   * @return the same set of features, expanded with all implied features
   */
  @CanIgnoreReturnValue
  public static Set<Feature<?>> addImpliedFeatures(Set<Feature<?>> features) {
    Queue<Feature<?>> queue = new ArrayDeque<>(features);
    while (!queue.isEmpty()) {
      Feature<?> feature = queue.remove();
      for (Feature<?> implied : feature.getImpliedFeatures()) {

   *
   * @param features the set of features to expand
   * @return the same set of features, expanded with all implied features
   */
  @CanIgnoreReturnValue
  public static Set<Feature<?>> addImpliedFeatures(Set<Feature<?>> features) {
    Queue<Feature<?>> queue = new ArrayDeque<>(features);
    while (!queue.isEmpty()) {
      Feature<?> feature = queue.remove();
      for (Feature<?> implied : feature.getImpliedFeatures()) {