* 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)

        Mockito.verify(context.logger)
                .info(
                        "  -a, --all             Apply all upgrades (equivalent to --model-version 4.1.0 --infer --model --plugins)");
    }

    @Test
    void testHelpIncludesDefaultBehavior() throws Exception {
        UpgradeContext context = createMockContext();

        help.execute(context);

                            || description.toLowerCase().contains("upgrade"),
                    "Description should mention model or upgrade");
        }
    }

    @Nested
    @DisplayName("Phase Upgrades")
    class PhaseUpgradeTests {

        @Test
        @DisplayName("should upgrade deprecated phases to Maven 4 equivalents in 4.1.0")

      }

      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(

    }

    /**
     * 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)");
        }

  }

  @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 ->

   [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.

This way, in case there was a breaking change for your code in one of the releases, you can still benefit from the previous upgrades. ✨

### Breaking Changes - Upgrade

* ⬆️ Upgrade Starlette to 0.16.0. PR [#4016](https://github.com/tiangolo/fastapi/pull/4016) by [@tiangolo](https://github.com/tiangolo).

Also upgrades the ranges of optional dependencies:

* `"jinja2 >=2.11.2,<4.0.0"`
* `"itsdangerous >=1.1.0,<3.0.0"`