// stop the replay go-routine.
	if h.store != nil {
		h.storeCtxCancel()
	}

	// Set logch to nil and close it.
	// This will block all Send operations,
	// and finish the existing ones.
	// All future ones will be discarded.
	h.logChMu.Lock()
	xioutil.SafeClose(h.logCh)
	h.logCh = nil
	h.logChMu.Unlock()

	if h.producer != nil {
		h.producer.Close()

     *   close(is);
     * }
     * </pre>
     * <p>
     * If an exception occurs in the try block, there is a possibility that an exception will also occur in the finally block's {@link #close(Closeable)}. If the exception is thrown from the finally block, the original exception from the try block will be lost.
     * </p>
     *
     * @param closeable the closeable object
     * @see Closeable#close()
     */

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

    why we're doing this and how to upgrade.

    The OkHttp 3.12.x branch will be our long-term branch for Android 2.3+ (API level 9+) and Java
    7+. These platforms lack support for TLS 1.2 and should not be used. But because upgrading is
    difficult we will backport critical fixes to the 3.12.x branch through December 31, 2021. (This

			}
			return err
		}
		target.firstPing = true
	}

	eventData, eErr := target.store.Get(key)
	if eErr != nil {
		// The last event key in a successful batch will be sent in the channel atmost once by the replayEvents()
		// Such events will not exist and would've been already been sent successfully.
		if os.IsNotExist(eErr) {
			return nil
		}
		return eErr
	}

   * called multiple times.
   *
   * <p>If {@link #stopAsync} is called on a {@link State#STARTING} service, this method is not
   * invoked immediately. Instead, it will be deferred until after the service is {@link
   * State#RUNNING}. Services that need to cancel startup work can override {@link #doCancelStart}.
   */
  @ForOverride
  protected abstract void doStop();

  /**

If you open the automatic API docs, your extension will show up at the bottom of the specific *path operation*.

<img src="/img/tutorial/path-operation-advanced-configuration/image01.png">

And if you see the resulting OpenAPI (at `/openapi.json` in your API), you will see your extension as part of the specific *path operation* too:

```JSON hl_lines="22"
{

	_, err := target.isActive()
	if err != nil {
		return err
	}

	eventData, err := target.store.Get(key)
	if err != nil {
		// The last event key in a successful batch will be sent in the channel atmost once by the replayEvents()
		// Such events will not exist and wouldve been already been sent successfully.
		if os.IsNotExist(err) {
			return nil
		}
		return err
	}

	if err = target.send(eventData); err != nil {

`FastAPI` is actually a sub-class of `Starlette`. So, if you already know or use Starlette, most of the functionality will work the same way.

With **FastAPI** you get all of **Starlette**'s features (as FastAPI is just Starlette on steroids):