s/41584243/runtimeerror-task-attached-to-a-different-loop" class="external-link" target="_blank">MongoDB's MotorClient</a>), remember to instantiate objects that need an event loop only within async functions, e.g. an `'@app.on_event("startup")` callback.

///...

  }

  /**
   * Streams lines from a {@link File}, stopping when our callback returns false, or we have read
   * all of the lines.
   *
   * @param file the file to read from
   * @param charset the charset used to decode the input stream; see {@link StandardCharsets} for
   *     helpful predefined constants
   * @param callback the {@link LineProcessor} to use to handle the lines

    )
    val call =
      client.newCall(
        Request.Builder()
          .url(server.url("/"))
          .build(),
      )
    val completionLatch = CountDownLatch(1)
    val callback: Callback =
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          completionLatch.countDown()
        }

        override fun onResponse(

 * may ultimately cause the application to slow down or crash.
 *
 * Both this class and [Response] implement [Closeable]. Closing a response simply
 * closes its response body. If you invoke [Call.execute] or implement [Callback.onResponse] you
 * must close this body by calling any of the following methods:
 *
 * * `Response.close()`
 * * `Response.body().close()`
 * * `Response.body().source().close()`

        // Load config files
        // ----------------------------------------------------------------------
        Map<String, String> paths = context.extraInterpolationSource();
        Function<String, String> callback =
                or(paths::get, prefix("cli.", userSpecifiedProperties::get), context.systemProperties::get);

        Path mavenConf;
        if (context.systemProperties.get(MAVEN_INSTALLATION_CONF) != null) {

    val request =
      Request.Builder()
        .url(url)
        .build()

    val promise = CompletableFuture<Response>()

    val call = client.newCall(request)
    call.enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          promise.completeExceptionally(e)
        }

        override fun onResponse(

          description: String to specify a shard for searching
          required: false
          schema:
            type: string
            example: abc
        - name: callback
          in: query
          description: Callback name for using JSONP
          required: false
          schema:
            type: string
      responses:
        '200':
          description: Successful operation

      queue.dispatch();
    } finally {
      logger.removeHandler(logHandler);
    }

    assertEquals(1, logHandler.getStoredLogRecords().size());
    assertEquals(
        "Exception while executing callback: MyListener custom-label",
        logHandler.getStoredLogRecords().get(0).getMessage());
  }

  public void testEnqueueAndDispatch_multithreaded() throws InterruptedException {
    Object listener = new Object();

      queue.dispatch();
    } finally {
      logger.removeHandler(logHandler);
    }

    assertEquals(1, logHandler.getStoredLogRecords().size());
    assertEquals(
        "Exception while executing callback: MyListener custom-label",
        logHandler.getStoredLogRecords().get(0).getMessage());
  }

  public void testEnqueueAndDispatch_multithreaded() throws InterruptedException {
    Object listener = new Object();

  /** The timestamp of the last taken event, used to measure elapsed time between events. */
  private var lastTimestampNs: Long? = null

  /** Confirm that the thread does not hold a lock on `lock` during the callback. */
  fun forbidLock(lock: Any) {
    forbiddenLocks.add(lock)
  }

  /**
   * Removes recorded events up to (and including) an event is found whose class equals [eventClass]
   * and returns it.
   */