assertThat(graph.adjacentNodes(node)).isEqualTo(asGraph.adjacentNodes(node));
      assertThat(graph.predecessors(node)).isEqualTo(asGraph.predecessors(node));
      assertThat(graph.successors(node)).isEqualTo(asGraph.successors(node));
      assertThat(graph.degree(node)).isEqualTo(asGraph.degree(node));
      assertThat(graph.inDegree(node)).isEqualTo(asGraph.inDegree(node));

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public abstract class AbstractCollectionTester<E extends @Nullable Object>
    extends AbstractContainerTester<Collection<E>, E> {

  // TODO: replace this with an accessor.
  protected Collection<E> collection;

  @Override
  protected Collection<E> actualContents() {
    return collection;
  }

  // TODO: dispose of this once collection is encapsulated.
  @Override

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public abstract class AbstractCollectionTester<E extends @Nullable Object>
    extends AbstractContainerTester<Collection<E>, E> {

  // TODO: replace this with an accessor.
  protected Collection<E> collection;

  @Override
  protected Collection<E> actualContents() {
    return collection;
  }

  // TODO: dispose of this once collection is encapsulated.
  @Override

    public Iterable<? extends Character> successors(Character node) {
      requestedNodes.add(node);
      return delegate.successors(node);
    }
  }

  private static <N> SuccessorsFunction<N> fixedSuccessors(Iterable<N> successors) {
    return new SuccessorsFunction<N>() {
      @Override
      public Iterable<N> successors(N n) {
        return successors;
      }
    };
  }

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getConfigId() {
        checkSpecifiedProperty("configId");
        return convertEmptyToNull(configId);
    }

  }

  @Override
  public Set<N> predecessors() {
    return Collections.unmodifiableSet(((BiMap<E, N>) inEdgeMap).values());
  }

  @Override
  public Set<N> successors() {
    return Collections.unmodifiableSet(((BiMap<E, N>) outEdgeMap).values());
  }

  @Override
  public Set<E> edgesConnecting(N node) {
    return new EdgesConnecting<>(((BiMap<E, N>) outEdgeMap).inverse(), node);

        .Builder()
        .add("content-length", "99")
        .add("authorization", "peanutbutter")
        .add("proxy-authorization", "chocolate")
        .add("cookie", "drink=coffee")
        .add("set-cookie", "accessory=sugar")
        .add("user-agent", "OkHttp")
        .build()
    assertThat(headers.toString()).isEqualTo(
      """
      |content-length: 99
      |authorization: ██
      |proxy-authorization: ██

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getUrlId() {
        checkSpecifiedProperty("urlId");
        return convertEmptyToNull(urlId);
    }

        return user.getName();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String[] getPermissions() {
        return user.getPermissions();
    }

    public String[] getRoles() {

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public LocalDateTime getCreatedAt() {
        checkSpecifiedProperty("createdAt");
        return createdAt;
    }