proxy_connect_timeout 300;
            
            # To support websocket
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            
            chunked_transfer_encoding off;

            proxy_pass http://console;
        }
    }

    }

    /**
     * Logs the upgrade options being used.
     */
    private void logUpgradeOptions(UpgradeContext context) {
        UpgradeOptions options = context.options();

        context.info("Options:");
        context.indent();

        if (options.all().orElse(false)) {
            context.info("all: true (applying all available upgrades)");
        }

            proxy_connect_timeout 300;
            
            # To support websocket
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            
            chunked_transfer_encoding off;

            proxy_pass http://console;
        }
    }

                || MODEL_VERSION_4_2_0.equals(modelVersion);
    }

    /**
     * Checks if an upgrade from one version to another is possible.
     *
     * @param fromVersion the source version
     * @param toVersion the target version
     * @return true if the upgrade is possible
     */
    public static boolean canUpgrade(String fromVersion, String toVersion) {

            proxy_connect_timeout 300;
            
            # To support websocket
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            
            chunked_transfer_encoding off;

            proxy_pass http://console;
        }
    }

    platform.assumeNotBouncyCastle()

    enableTls(Protocol.HTTP_1_1)
    upgrade()
  }

  @Test
  fun upgradeRefusedByServer() {
    server.enqueue(MockResponse(body = "normal request"))
    val requestWithUpgrade =
      Request
        .Builder()
        .url(server.url("/"))
        .header("Connection", "upgrade")
        .build()
    client.newCall(requestWithUpgrade).execute().use { response ->

* `upgrade`: Upgrades

      }

      val isUpgradeResponse =
        isUpgradeCode &&
          "upgrade".equals(response.header("Connection"), ignoreCase = true)

      response =
        when {
          // This is an HTTP/1 upgrade. (This case includes web socket upgrades.)
          isUpgradeRequest && isUpgradeResponse -> {
            response
              .newBuilder()
              .body(

    coders call this and we don't want their users to suffer.


## Version 4.0.0

_2019-06-26_

**This release upgrades OkHttp to Kotlin.** We tried our best to make fast and safe to upgrade
from OkHttp 3.x. We wrote an [upgrade guide][upgrading_to_okhttp_4] to help with the migration and a
[blog post][okhttp4_blog_post] to explain it.

 *  Fix: Target Java 8 bytecode for Java and Kotlin.

   [Gradle plugin][japicmp_gradle] to enforce binary compatibility.

 * **Java source compatibility** is the ability to upgrade Java uses of OkHttp 3.x to 4.x without
   changing `.java` files.

 * **Kotlin source compatibility** is the ability to upgrade Kotlin uses of OkHttp 3.x to 4.x
   without changing `.kt` files.

With a few small exceptions (below), OkHttp 4.x is both binary- and Java source-compatible with