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;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.testing.features.ConflictingRequirementsException;

  }

  @Override
  public Set<N> predecessors() {
    return Collections.unmodifiableSet(((BiMap<E, N>) inEdgeMap).values());
  }

  @Override
  public Set<N> successors() {
    return Collections.unmodifiableSet(((BiMap<E, N>) outEdgeMap).values());
  }

  @Override
  public Set<E> edgesConnecting(N node) {

  }

  @Override
  public Set<N> predecessors() {
    return Collections.unmodifiableSet(((BiMap<E, N>) inEdgeMap).values());
  }

  @Override
  public Set<N> successors() {
    return Collections.unmodifiableSet(((BiMap<E, N>) outEdgeMap).values());
  }

  @Override
  public Set<E> edgesConnecting(N node) {

      }
    };
  }

  @Override
  public Set<E> inEdges() {
    return Collections.unmodifiableSet(inEdgeMap.keySet());
  }

  @Override
  public Set<E> outEdges() {
    return Collections.unmodifiableSet(outEdgeMap.keySet());
  }

  @Override
  public N adjacentNode(E edge) {
    // Since the reference node is defined to be 'source' for directed graphs,

                Set<String> innerSet = new HashSet<>();
                Collections.addAll(innerSet, elements);
                return unmodifiableSet(innerSet);
              }
            })
        .named("unmodifiableSet/HashSet")
        .withFeatures(
            CollectionFeature.NONE,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.ALLOWS_NULL_VALUES,

  }

  @LazyInit private transient @Nullable Reference<Multiset<N>> predecessorsReference;

  @Override
  public Set<N> predecessors() {
    return Collections.unmodifiableSet(predecessorsMultiset().elementSet());
  }

  private Multiset<N> predecessorsMultiset() {
    Multiset<N> predecessors = getReference(predecessorsReference);
    if (predecessors == null) {

  }

  @LazyInit private transient @Nullable Reference<Multiset<N>> predecessorsReference;

  @Override
  public Set<N> predecessors() {
    return Collections.unmodifiableSet(predecessorsMultiset().elementSet());
  }

  private Multiset<N> predecessorsMultiset() {
    Multiset<N> predecessors = getReference(predecessorsReference);
    if (predecessors == null) {

                Set<String> innerSet = new HashSet<>();
                Collections.addAll(innerSet, elements);
                return unmodifiableSet(innerSet);
              }
            })
        .named("unmodifiableSet/HashSet")
        .withFeatures(
            CollectionFeature.NONE,
            CollectionFeature.SERIALIZABLE,
            CollectionFeature.ALLOWS_NULL_VALUES,

 * limitations under the License.
 */

package com.google.common.collect;

import static java.util.Collections.emptySet;
import static java.util.Collections.unmodifiableSet;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;

import static com.google.common.collect.testing.Helpers.assertEqualInOrder;
import static com.google.common.collect.testing.Platform.format;
import static java.util.Arrays.asList;
import static java.util.Collections.unmodifiableSet;
import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.assertFalse;
import static junit.framework.Assert.assertTrue;
import static junit.framework.Assert.fail;