*/
    @Nonnull
    Optional<Boolean> plugins();

    /**
     * Should apply all upgrade options (equivalent to --model-version 4.1.0 --infer --model --plugins).
     * This is a convenience option that combines model upgrade, inference, compatibility fixes, and plugin upgrades.
     *
     * @return an {@link Optional} containing the boolean value {@code true} if specified, or empty
     */
    @Nonnull

* `upgrade`: Upgrades

- For installations using Systemd MinIO service, upgrade via RPM/DEB packages **parallelly** on all servers or replace the binary lets say `/opt/bin/minio` on all nodes, apply executable permissions `chmod +x /opt/bin/minio` and process to perform `mc admin service restart alias/`.

### Upgrade Checklist

- Test all upgrades in a lower environment (DEV, QA, UAT) before applying to production. Performing blind upgrades in production environments carries significant risk.

 * that it is not "API-frozen."
 *
 * <p>It is generally safe for <i>applications</i> to depend on beta APIs, at the cost of some extra
 * work during upgrades. However it is generally inadvisable for <i>libraries</i> (which get
 * included on users' CLASSPATHs, outside the library developers' control) to do so.
 *
 * @author Kevin Bourrillion
 */
@Retention(RetentionPolicy.CLASS)

 * that it is not "API-frozen."
 *
 * <p>It is generally safe for <i>applications</i> to depend on beta APIs, at the cost of some extra
 * work during upgrades. However it is generally inadvisable for <i>libraries</i> (which get
 * included on users' CLASSPATHs, outside the library developers' control) to do so.
 *
 * @author Kevin Bourrillion
 */
@Retention(RetentionPolicy.CLASS)

  }

  @Test
  fun upgradeHttps() {
    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 ->

      }

      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(

restart alias/`. - For installations using Systemd MinIO service, upgrade via RPM/DEB packages **parallelly** on all servers or replace the binary lets say `/opt/bin/minio` on all nodes, apply executable permissions `chmod +x /opt/bin/minio` and process to perform `mc admin service restart alias/`. ### Upgrade Checklist - Test all upgrades in a lower environment (DEV, QA, UAT) before applying to production. Performing blind upgrades in production environments carries significant risk. - Read the release...

   [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

    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.