*  **Canceling batches of calls is now the application's responsibility.**
    The API to cancel calls by tag has been removed and replaced with a more
    general mechanism. The dispatcher now exposes all in-flight calls via its
    `runningCalls()` and `queuedCalls()` methods. You can write code that
    selects calls by tag, host, or whatever, and invokes `Call.cancel()` on the
    ones that are no longer necessary.

  - New objects inherit the retention settings of the bucket object lock configuration automatically
  - Retention headers can be optionally set while uploading objects
  - Once objects are uploaded PutObjectRetention API can be called to change retention settings
- *MINIO_NTP_SERVER* environment variable can be set to remote NTP server endpoint if system time is not desired for setting retention dates.

## Explore Further

    * `bearer`: a header `Authorization` with a value of `Bearer ` plus a token. This is inherited from OAuth2.
    * HTTP Basic authentication.
    * HTTP Digest, etc.
* `oauth2`: all the OAuth2 ways to handle security (called "flows").
    * Several of these flows are appropriate for building an OAuth 2.0 authentication provider (like Google, Facebook, Twitter, GitHub, etc):
        * `implicit`
        * `clientCredentials`

    1)
        # If $1=1 this is an install
        IS_UPGRADE=false
    ;;
    2)
        # If $1=1 this is an upgrade
        IS_UPGRADE=true
    ;;

    *)
        echo "post install script called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac

if [ "x$IS_UPGRADE" != "xtrue" ]; then
    if command -v systemctl >/dev/null; then

    return null
  }

  /**
   * Cancel all calls currently enqueued or executing. Includes calls executed both
   * [synchronously][Call.execute] and [asynchronously][Call.enqueue].
   */
  fun cancelAll() {
    this.withLock {
      for (call in readyAsyncCalls) {
        call.call.cancel()
      }
      for (call in runningAsyncCalls) {
        call.call.cancel()
      }
      for (call in runningSyncCalls) {

      assertEquals(Protocol.HTTP_2, response.protocol)
    }

    // Only logs to the test logger above
    // Will fail if "adb shell setprop log.tag.okhttp.Http2 DEBUG" is called
    assertEquals(setOf(OkHttpTest::class.java.name), testHandler.calls.keys)
  }

  fun testCachedRequest() {
    enableTls()

    server.enqueue(MockResponse(body = "abc", headers = Headers.headersOf("cache-control", "public, max-age=3")))

        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="7"
    {!> ../../../docs_src/request_forms/tutorial001.py!}
    ```

For example, in one of the ways the OAuth2 specification can be used (called "password flow") it is required to send a `username` and `password` as form fields.

The <abbr title="specification">spec</abbr> requires the fields to be exactly named `username` and `password`, and to be sent as form fields, not JSON.

  }

  /**
   * Callers of this method are not thread safe, and sometimes on application threads. Most often,
   * this method will be called to send a buffer worth of data to the peer.
   *
   * Writes are subject to the write window of the stream and the connection. Until there is a
   * window sufficient to send [byteCount], the caller will block. For example, a user of

         * Please keep this code in sync.
         */
        internal
        fun generateImportPackages(): List<String> {
            /*
             * The class that getResource called upon must be from within a jar that contains the import txt file.
             *
             * Note: Even though 'jump to declaration' in IJ will show this to be the 'DefaultImportsReader' from

    {!> ../../../docs_src/settings/app03/main.py!}
    ```

Then for any subsequent calls of `get_settings()` in the dependencies for the next requests, instead of executing the internal code of `get_settings()` and creating a new `Settings` object, it will return the same object that was returned on the first call, again and again.

#### `lru_cache` Technical Details