? (ImmutableNetwork<N, E>) network
        : new ImmutableNetwork<N, E>(network);
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   */
  @InlineMe(
      replacement = "checkNotNull(network)",
      staticImports = "com.google.common.base.Preconditions.checkNotNull")
  @Deprecated
  public static <N, E> ImmutableNetwork<N, E> copyOf(ImmutableNetwork<N, E> network) {

import org.junit.runners.JUnit4;

/** Tests for {@link ImmutableNetwork}. */
@RunWith(JUnit4.class)
@NullUnmarked
public class ImmutableNetworkTest {

  @Test
  public void immutableNetwork() {
    MutableNetwork<String, Integer> mutableNetwork = NetworkBuilder.directed().build();
    mutableNetwork.addNode("A");
    ImmutableNetwork<String, Integer> immutableNetwork = ImmutableNetwork.copyOf(mutableNetwork);

import org.junit.runners.JUnit4;

/** Tests for {@link ImmutableNetwork}. */
@RunWith(JUnit4.class)
@NullUnmarked
public class ImmutableNetworkTest {

  @Test
  public void immutableNetwork() {
    MutableNetwork<String, Integer> mutableNetwork = NetworkBuilder.directed().build();
    mutableNetwork.addNode("A");
    ImmutableNetwork<String, Integer> immutableNetwork = ImmutableNetwork.copyOf(mutableNetwork);

      NetworkBuilder.directed().allowsSelfLoops(true).expectedNodeCount(16);

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

        .edgeOrder(network.edgeOrder());
  }

  /**
   * Returns an {@link ImmutableNetwork.Builder} with the properties of this {@link NetworkBuilder}.
   *
   * <p>The returned builder can be used for populating an {@link ImmutableNetwork}.
   *
   * @since 28.0
   */
  public <N1 extends N, E1 extends E> ImmutableNetwork.Builder<N1, E1> immutable() {
    NetworkBuilder<N1, E1> castBuilder = cast();

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 {

      NetworkBuilder.directed().allowsSelfLoops(true).expectedNodeCount(16);

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

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 {