val next = copy(index = index + 1, request = request)
    val interceptor = interceptors[index]

    @Suppress("USELESS_ELVIS")
    val response =
      interceptor.intercept(next) ?: throw NullPointerException(
        "interceptor $interceptor returned null",
      )

    if (exchange != null) {
      check(index + 1 >= interceptors.size || next.calls == 1) {

      throw AssertionError(e)
    } catch (e: InvocationTargetException) {
      // https://github.com/square/okhttp/issues/5587
      val cause = e.cause
      when {
        cause is NullPointerException && cause.message == "ssl == null" -> null
        else -> throw AssertionError(e)
      }
    }
  }

  companion object {
    val playProviderFactory: DeferredSocketAdapter.Factory =

    private class DnsSystem : Dns {
      override fun lookup(hostname: String): List<InetAddress> {
        try {
          return InetAddress.getAllByName(hostname).toList()
        } catch (e: NullPointerException) {
          throw UnknownHostException("Broken system behaviour for dns lookup of $hostname").apply {
            initCause(e)
          }
        }
      }
    }
  }

  fun onlyRoute() = routes.single()

  @Throws(IOException::class)
  override fun authenticate(
    route: Route?,
    response: Response,
  ): Request? {
    if (route == null) throw NullPointerException("route == null")
    responses += response
    routes += route
    if (!schemeMatches(response) || credential == null) return null
    val header =
      when (response.code) {
        407 -> "Proxy-Authorization"

        .build()
    assertThat(headers.toString()).isEqualTo("header1: valué1\n")
  }

  // Fails on JS, ClassCastException: Illegal cast
  @Test fun ofMapThrowsOnNull() {
    assertFailsWith<NullPointerException> {
      (mapOf("User-Agent" to null) as Map<String, String>).toHeaders()
    }
  }

  @Test fun toMultimapGroupsHeaders() {
    val headers =
      Headers.headersOf(
        "cache-control",