*/

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

import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_QUERIES;
import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;

import com.google.common.annotations.GwtCompatible;

 * Preconditions}</a>.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible
public final class Preconditions {
  private Preconditions() {}

  /**
   * Ensures the truth of an expression involving one or more parameters to the calling method.
   *
   * @param expression a boolean expression
   * @throws IllegalArgumentException if {@code expression} is false
   */

import static com.google.common.collect.testing.features.FeatureUtil.getTesterAnnotations;
import static com.google.common.collect.testing.features.FeatureUtil.impliedFeatures;
import static com.google.common.collect.testing.features.FeatureUtilTest.ExampleFeature.BAR;
import static com.google.common.collect.testing.features.FeatureUtilTest.ExampleFeature.FOO;

        (TestMultisetGenerator<E>) parentBuilder.getSubjectGenerator();

    Set<Feature<?>> features = new HashSet<>();
    features.add(NoRecurse.SUBMULTISET);
    features.add(RESTRICTS_ELEMENTS);
    features.addAll(parentBuilder.getFeatures());

    if (!features.remove(SERIALIZABLE_INCLUDING_VIEWS)) {
      features.remove(SERIALIZABLE);
    }

import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION;
import static com.google.common.collect.testing.features.CollectionFeature.RESTRICTS_ELEMENTS;
import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ADD;

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEY_QUERIES;
import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE;

import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.testing.EqualsTester;

      new HashMap<>();

  /**
   * Given a set of features, add to it all the features directly or indirectly implied by any of
   * them, and return it.
   *
   * @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);