[PyQt] Strange error with QtBluetooth.QLowEnergyService

[s.achterop at rug.nl]

   Hello list,

I am working on a BLE app on PyQt5 and am getting an error I don't understand.

With the following snippet:

    from PyQt5 import QtBluetooth as QtBt

    QtBt.QLowEnergyService.writeCharacteristic(QtBt.QLowEnergyCharacteristic.Unknown, 'asdf')

I get the following error:

   TypeError: writeCharacteristic(self, QLowEnergyCharacteristic, Union[QByteArray, bytes, bytearray], ...
       ... mode: QLowEnergyService.WriteMode = QLowEnergyService.WriteWithResponse): first argument of unbound method must have type 'QLowEnergyService'

But from what I see, the type is correct.
What am doing wrong here?

   Thanks in advance,
      Sietse