@Override
	final void cancelQueue() {
		emptyTasks(FailCallback.REASON_CANCELLED);
		initialization = false;

		final BluetoothDevice device = bluetoothDevice;
		if (device == null)
			return;

		if (operationInProgress) {
			cancelCurrent();
		}

		if (connectRequest != null) {
			connectRequest.notifyFail(device, FailCallback.REASON_CANCELLED);
			connectRequest = null;
			internalDisconnect(ConnectionObserver.REASON_CANCELLED);
		}
	}
Enqueues the given request at the front of the the init or task queue, depending
on whether the initialization is in progress, or not.
<p>
This method sets the {@link #operationInProgress} to false, assuming the newly added
request will be executed immediately after this method ends.

@param request the request to be added.
ble/src/main/java/no/nordicsemi/android/ble/BleManagerHandler.java