Adding ArcGIS-FeatureServer-Layer to QGIS using PyQGIS?

After all, the answer is quite simple (but nowhere documented):

uri = "crs='EPSG:25832' filter='' url='http://someurl.com/featureserver' table="" sql="
my_layer = QgsVectorLayer(uri, "layername", "arcgisfeatureserver")

The lack of documentation leads to a lot of other questions (bounding-box, username, password, ...)