responses += response
    routes += route
    if (!schemeMatches(response) || credential == null) return null
    val header =
      when (response.code) {
        407 -> "Proxy-Authorization"
        else -> "Authorization"
      }
    return response.request
      .newBuilder()
      .addHeader(header, credential)
      .build()
  }

  private fun schemeMatches(response: Response): Boolean {