import java.util.Collections;
import java.util.Optional;
import java.util.Set;
import org.jspecify.annotations.NullUnmarked;
import org.junit.After;
import org.junit.Test;

/**
 * Abstract base class for testing directed {@link Network} implementations defined in this package.
 */
@NullUnmarked
public abstract class AbstractStandardDirectedNetworkTest extends AbstractNetworkTest {

  @After
  public void validateSourceAndTarget() {

        ImmutableNetwork.copyOf(NetworkBuilder.directed().<String, String>build());
    Network<String, String> network2 = ImmutableNetwork.copyOf(network1);

    assertThat(network2).isSameInstanceAs(network1);
  }

  @Test
  public void edgesConnecting_directed() {
    MutableNetwork<String, String> mutableNetwork =
        NetworkBuilder.directed().allowsSelfLoops(true).build();

    Graph<String> graph1 = ImmutableGraph.copyOf(GraphBuilder.directed().<String>build());
    Graph<String> graph2 = ImmutableGraph.copyOf(graph1);

    assertThat(graph2).isSameInstanceAs(graph1);
  }

  @Test
  public void immutableGraphBuilder_appliesGraphBuilderConfig() {
    ImmutableGraph<String> emptyGraph =
        GraphBuilder.directed()
            .allowsSelfLoops(true)

 * Thread1: acquire(LockA) --X acquire(LockB)
 * Thread2: acquire(LockB) --X acquire(LockC)
 * ...
 * ThreadN: acquire(LockN) --X acquire(LockA)
 * </pre>
 *
 * <p>The implementation detects cycles by constructing a directed graph in which each lock
 * represents a node and each edge represents an acquisition ordering between two locks.
 *
 * <ul>
 *   <li>Each lock adds (and removes) itself to/from a ThreadLocal Set of acquired locks when the

  private static final ImmutableNetwork<String, String> IMMUTABLE_NETWORK_B =
      NetworkBuilder.directed().<String, String>immutable().addNode("B").build();

  public PackageSanityTests() {
    MutableNetwork<String, String> mutableNetworkA = NetworkBuilder.directed().build();
    mutableNetworkA.addNode("a");
    MutableNetwork<String, String> mutableNetworkB = NetworkBuilder.directed().build();

        ImmutableValueGraph.copyOf(ValueGraphBuilder.directed().<String, Integer>build());
    ValueGraph<String, Integer> graph2 = ImmutableValueGraph.copyOf(graph1);

    assertThat(graph2).isSameInstanceAs(graph1);
  }

  @Test
  public void incidentEdgeOrder_stable() {
    ImmutableValueGraph<String, Integer> immutableValueGraph =
        ImmutableValueGraph.copyOf(ValueGraphBuilder.directed().<String, Integer>build());

  // Node order tests

  @Test
  public void nodeOrder_none() {
    MutableGraph<Integer> graph = GraphBuilder.directed().nodeOrder(unordered()).build();

    assertThat(graph.nodeOrder()).isEqualTo(unordered());
  }

  @Test
  public void nodeOrder_insertion() {
    MutableGraph<Integer> graph = GraphBuilder.directed().nodeOrder(insertion()).build();

    addNodes(graph);

    assertThat(graph.nodeOrder()).isEqualTo(insertion());

  private static final ImmutableNetwork<String, String> IMMUTABLE_NETWORK_B =
      NetworkBuilder.directed().<String, String>immutable().addNode("B").build();

  public PackageSanityTests() {
    MutableNetwork<String, String> mutableNetworkA = NetworkBuilder.directed().build();
    mutableNetworkA.addNode("a");
    MutableNetwork<String, String> mutableNetworkB = NetworkBuilder.directed().build();

        ImmutableValueGraph.copyOf(ValueGraphBuilder.directed().<String, Integer>build());
    ValueGraph<String, Integer> graph2 = ImmutableValueGraph.copyOf(graph1);

    assertThat(graph2).isSameInstanceAs(graph1);
  }

  @Test
  public void incidentEdgeOrder_stable() {
    ImmutableValueGraph<String, Integer> immutableValueGraph =
        ImmutableValueGraph.copyOf(ValueGraphBuilder.directed().<String, Integer>build());

    MutableGraph<Integer> directedGraph = GraphBuilder.directed().allowsSelfLoops(false).build();
    directedGraph.putEdge(N1, N2);
    directedGraph.putEdge(N1, N3);
    directedGraph.putEdge(N2, N3);
    directedGraph.addNode(N4);

    MutableGraph<Integer> expectedClosure = GraphBuilder.directed().allowsSelfLoops(true).build();
    expectedClosure.putEdge(N1, N1);
    expectedClosure.putEdge(N1, N2);