// Silently replace web socket URLs with HTTP URLs.
    private fun canonicalUrl(url: String) =
      when {
        url.startsWith("ws:", ignoreCase = true) -> "http:${url.substring(3)}"
        url.startsWith("wss:", ignoreCase = true) -> "https:${url.substring(4)}"
        else -> url
      }

    /**
     * Sets the URL target of this request.
     *