//
  // Graph properties
  //

  /**
   * Returns true if the edges in this graph are directed. Directed edges connect a {@link
   * EndpointPair#source() source node} to a {@link EndpointPair#target() target node}, while
   * undirected edges connect a pair of nodes to each other.
   */
  @Override
  boolean isDirected();

  /**

import org.jspecify.annotations.Nullable;

/**
 * An immutable pair representing the two endpoints of an edge in a graph. The {@link EndpointPair}
 * of a directed edge is an ordered pair of nodes ({@link #source()} and {@link #target()}). The
 * {@link EndpointPair} of an undirected edge is an unordered pair of nodes ({@link #nodeU()} and
 * {@link #nodeV()}).
 *
 * <p>The edge is a self-loop if, and only if, the two endpoints are equal.
 *

import java.util.Collection;
import org.jspecify.annotations.NullUnmarked;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

/** Tests for a directed {@link ImmutableNetwork}. */
@AndroidIncompatible
@RunWith(Parameterized.class)
@NullUnmarked
public class StandardImmutableDirectedNetworkTest extends AbstractStandardDirectedNetworkTest {

# The environment overrides everything else.

# Use the Go module mirror and checksum database by default.
# See https://proxy.golang.org for details.
GOPROXY=https://proxy.golang.org,direct
GOSUMDB=sum.golang.org

# Automatically download newer toolchains as directed by go.mod files.
# See https://go.dev/doc/toolchain for details.

 */
public enum WitnessEventType {
    /**
     * Resource state changed - general resource state modification
     */
    RESOURCE_CHANGE(1),

    /**
     * Client should move to different node - directed failover
     */
    CLIENT_MOVE(2),

    /**
     * Share moved to different node - share mobility event
     */
    SHARE_MOVE(3),

    /**
     * IP address changed - network configuration change

 * <p>This class maintains a map of nodes to {@link NetworkConnections}. This class also maintains a
 * map of edges to reference nodes. The reference node is defined to be the edge's source node on
 * directed graphs, and an arbitrary endpoint of the edge on undirected graphs.
 *
 * <p>Collection-returning accessors return unmodifiable views: the view returned will reflect
 * changes to the graph (if the graph is mutable) but may not be modified by the user.
 *

import java.util.Collection;
import org.jspecify.annotations.NullUnmarked;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

/** Tests for a directed {@link StandardMutableGraph}. */
@AndroidIncompatible
@RunWith(Parameterized.class)
@NullUnmarked
public final class StandardImmutableDirectedGraphTest extends AbstractStandardDirectedGraphTest {

import java.util.Collection;
import org.jspecify.annotations.NullUnmarked;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

/** Tests for a directed {@link StandardMutableGraph}. */
@AndroidIncompatible
@RunWith(Parameterized.class)
@NullUnmarked
public final class StandardMutableDirectedGraphTest extends AbstractStandardDirectedGraphTest {

import java.util.Collection;
import org.jspecify.annotations.NullUnmarked;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

/** Tests for a directed {@link StandardMutableGraph}. */
@AndroidIncompatible
@RunWith(Parameterized.class)
@NullUnmarked
public final class StandardMutableDirectedGraphTest extends AbstractStandardDirectedGraphTest {

import com.google.common.collect.ImmutableBiMap;
import java.util.Collections;
import java.util.Map;
import java.util.Set;

/**
 * An implementation of {@link NetworkConnections} for directed networks.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
final class DirectedNetworkConnections<N, E> extends AbstractDirectedNetworkConnections<N, E> {