copy and paste [ObsoleteUrlFactory.java][obsolete_url_factory] or
    [ObsoleteApacheClient.java][obsolete_apache_client] into your project.

 *  **OkHttp now supports duplex calls over HTTP/2.** With normal HTTP calls the request must finish
    before the response starts. With duplex, request and response bodies are transmitted

 * forgiving: it will automatically percent-encode the `|'` yielding `http://example.com/abc%7Cdef`.
 * This kind behavior is consistent with web browsers. `HttpUrl` prefers consistency with major web
 * browsers over consistency with obsolete specifications.
 *
 * ### Paths and Queries should decompose
 *
 * Neither of the built-in URL models offer direct access to path segments or query parameters.

          this.routeDatabase = null
        }
        this.dns = dns
      }

    /**
     * Sets the HTTP proxy that will be used by connections created by this client. This takes
     * precedence over [proxySelector], which is only honored when this proxy is null (which it is
     * by default). To disable proxy use completely, call `proxy(Proxy.NO_PROXY)`.
     */
    fun proxy(proxy: Proxy?) =
      apply {