Pipe Pressure Loss - Change Coefficient In RVT

Hi

I have tried changing the Pipe Pressure Loss in an RVT in the same way as was achieved in this link @Kulkul:

In the Python script I have changed the duct lines to the following:
param = fitting.get_Parameter(BuiltInParameter.RBS_PIPE_FITTING_LOSS_METHOD_SERVER_PARAM)
lc = getLossMethods(ExternalServices.BuiltInExternalServices.PipeFittingAndAccessoryPressureDropService)

For some reason I have the error shown in this image: Error