import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.SampleElements.Colliders;
import java.util.List;

/**
 * A generator using sample elements whose hash codes all collide badly.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestCollidingSetGenerator implements TestSetGenerator<Object> {
  @Override

      }

      assertThat(network.nodes()).hasSize(NUM_NODES - numNodesToRemove);
      // Number of edges remaining is unknown (node's incident edges have been removed).
      AbstractNetworkTest.validateNetwork(network);

      for (int i = numNodesToRemove; i < NUM_NODES; ++i) {
        assertThat(network.removeNode(nodeList.get(i))).isTrue();
      }

      assertThat(network.nodes()).isEmpty();

      }

      assertThat(network.nodes()).hasSize(NUM_NODES - numNodesToRemove);
      // Number of edges remaining is unknown (node's incident edges have been removed).
      AbstractNetworkTest.validateNetwork(network);

      for (int i = numNodesToRemove; i < NUM_NODES; ++i) {
        assertThat(network.removeNode(nodeList.get(i))).isTrue();
      }

      assertThat(network.nodes()).isEmpty();

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.SampleElements.Colliders;
import java.util.List;

/**
 * A generator using sample elements whose hash codes all collide badly.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestCollidingSetGenerator implements TestSetGenerator<Object> {
  @Override

   * Arrays#hashCode(Object[])}. Note that array arguments to this method, with the exception of a
   * single Object array, do not get any special handling; their hash codes are based on identity
   * and not contents.
   *
   * <p>This is useful for implementing {@link Object#hashCode()}. For example, in an object that
   * has three properties, {@code x}, {@code y}, and {@code z}, one could write:

    checkNotNull(nodeU);
    checkNotNull(nodeV);
    return nodes().contains(nodeU) && successors(nodeU).contains(nodeV);
  }

  @Override
  public boolean hasEdgeConnecting(EndpointPair<N> endpoints) {
    checkNotNull(endpoints);
    if (!isOrderingCompatible(endpoints)) {
      return false;
    }
    N nodeU = endpoints.nodeU();
    N nodeV = endpoints.nodeV();

  /** Returns the children of the specified node. Must not contain null. */
  public abstract Iterable<T> children(T root);

  /**
   * Returns an unmodifiable iterable over the nodes in a tree structure, using pre-order traversal.
   * That is, each node's subtrees are traversed after the node itself is returned.
   *
   * <p>No guarantees are made about the behavior of the traversal when nodes change while iteration

   * Returns true if there is an edge that directly connects {@code nodeU} to {@code nodeV}. This is
   * equivalent to {@code nodes().contains(nodeU) && successors(nodeU).contains(nodeV)}.
   *
   * <p>In an undirected graph, this is equal to {@code hasEdgeConnecting(nodeV, nodeU)}.
   *
   * @since 23.0
   */
  boolean hasEdgeConnecting(N nodeU, N nodeV);

  /**

    return hasEdgeConnectingInternal(checkNotNull(nodeU), checkNotNull(nodeV));
  }

  @Override
  public boolean hasEdgeConnecting(EndpointPair<N> endpoints) {
    checkNotNull(endpoints);
    return isOrderingCompatible(endpoints)
        && hasEdgeConnectingInternal(endpoints.nodeU(), endpoints.nodeV());
  }

  @Override
  @CheckForNull

    checkArgument(containsNode(nodeV), NODE_NOT_IN_GRAPH, nodeV);
    return nodePairInvalidatableSet(connectionsU.edgesConnecting(nodeV), nodeU, nodeV);
  }

  @Override
  public Set<E> inEdges(N node) {
    return nodeInvalidatableSet(checkedConnections(node).inEdges(), node);
  }

  @Override
  public Set<E> outEdges(N node) {
    return nodeInvalidatableSet(checkedConnections(node).outEdges(), node);
  }

  @Override