// repeat the request (even non-idempotent ones.)
        if (!client.retryOnConnectionFailure) {
          // The application layer has directed us not to retry the request.
          return null
        }

        val requestBody = userResponse.request.body
        if (requestBody != null && requestBody.isOneShot()) {
          return null
        }

 *
 * <ul>
 *   <li>Test cases related to whether the graph is directed, undirected, mutable, or immutable.
 *   <li>Test cases related to the specific implementation of the {@link Network} interface.
 * </ul>
 *
 * TODO(user): Make this class generic (using <N, E>) for all node and edge types.
 * TODO(user): Differentiate between directed and undirected edge strings.
 */
public abstract class AbstractNetworkTest {

import com.google.common.collect.ImmutableList;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/**
 * Standard implementation of {@link MutableNetwork} that supports both directed and undirected
 * graphs. Instances of this class should be constructed with {@link NetworkBuilder}.
 *
 * <p>Time complexities for mutation methods are all O(1) except for {@code removeNode(N node)},

        * Is this turned on by default?
        * How many users are affected by this change?

## Feature implementation

Release managers will continue to have a final say in what gets merged or not, unless directed by the TOC. See the next
section if the implementation is done, but a bug is being addressed.

* Any code that changes feature functionality must be done within 2 weeks of the release branch cutting. Even then it is

 *
 * <ul>
 *   <li>Test cases related to whether the graph is directed or undirected.
 *   <li>Test cases related to the specific implementation of the {@link Graph} interface.
 * </ul>
 *
 * TODO(user): Make this class generic (using <N, E>) for all node and edge types.
 * TODO(user): Differentiate between directed and undirected edge strings.
 */
public abstract class AbstractGraphTest {

 * iteration order guarantees.
 *
 * <p>Example usage:
 *
 * <pre>{@code
 * MutableGraph<Integer> graph =
 *     GraphBuilder.directed().nodeOrder(ElementOrder.<Integer>natural()).build();
 * }</pre>
 *
 * @author Joshua O'Madadhain
 * @since 20.0
 */
@Beta
@Immutable
@ElementTypesAreNonnullByDefault
public final class ElementOrder<T> {

 * iteration order guarantees.
 *
 * <p>Example usage:
 *
 * <pre>{@code
 * MutableGraph<Integer> graph =
 *     GraphBuilder.directed().nodeOrder(ElementOrder.<Integer>natural()).build();
 * }</pre>
 *
 * @author Joshua O'Madadhain
 * @since 20.0
 */
@Beta
@Immutable
@ElementTypesAreNonnullByDefault
public final class ElementOrder<T> {

 * 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

import com.google.common.collect.ImmutableSet;
import java.util.Collections;
import java.util.Set;
import org.junit.After;
import org.junit.Test;

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

  @After
  public void validateSourceAndTarget() {

import com.google.common.collect.ImmutableSet;
import java.util.Collections;
import java.util.Optional;
import java.util.Set;
import org.junit.After;
import org.junit.Test;

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

  @After
  public void validateSourceAndTarget() {