@NonNull
	protected WriteRequest disableNotifications(@Nullable final BluetoothGattCharacteristic characteristic) {
		return Request.newDisableNotificationsRequest(characteristic)
				.setRequestHandler(requestHandler);
	}
Disables notifications on given characteristic.
If the characteristic is null, the {@link Request#fail(FailCallback) fail(FailCallback)}
callback will be called.
<p>
The returned request must be either enqueued using {@link Request#enqueue()} for
asynchronous use, or awaited using await() in synchronous execution.

@param characteristic the characteristic to be disabled.
@return The request.
ble/src/main/java/no/nordicsemi/android/ble/BleManager.java