* be updated after modifications to {@code graph}.
   *
   * @since 33.1.0 (present with return type {@code Graph} since 20.0)
   */
  // TODO(b/31438252): Consider potential optimizations for this algorithm.
  public static <N> ImmutableGraph<N> transitiveClosure(Graph<N> graph) {
    ImmutableGraph.Builder<N> transitiveClosure =
        GraphBuilder.from(graph).allowsSelfLoops(true).<N>immutable();

    public static final String UNSAFE_URL = "unsafe-url";
  }

  /**
   * The HTTP <a href="https://www.w3.org/TR/service-workers/#update-algorithm">{@code
   * Service-Worker}</a> header field name.
   *
   * @since 20.0
   */
  public static final String SERVICE_WORKER = "Service-Worker";
  /** The HTTP {@code TE} header field name. */