setNormRange does not work when doing an extended fit apparently!

fit_extended.py

## setNormRange does not work when doing an extended fit apparently!

import scipy.integrate
import numpy
import matplotlib.pyplot as plt
from ROOT import *
gErrorIgnoreLevel = kInfo;

points = [ 4630.206,  4905.73 ,  5030.952,  4475.197,  4425.941,  4808.518, 4500.441,  4647.756,  4629.322,  5752.579,  4847.882,  6035.395, 4432.979,  4382.774,  4591.621]
ranges = [(4360.,5020.),(5626,6360)]

mass = RooRealVar("B_s0_MM","B_s0_MM", 4360., 6360., "MeV")
mass.setRange("fitRangeLeft",  ranges[0][0] , ranges[0][1])
mass.setRange("fitRangeRight", ranges[1][0], ranges[1][1])

data = RooDataSet("data","data", RooArgSet(mass))
for point in points:
    mass.setVal(point)
    data.addFast(RooArgSet(mass))


## First do normal fit

exponent1 = RooRealVar("exponent","exponent", 0, -1., 1.)
data_model1 = RooExponential("data_model", "data_model", mass, exponent1);


data_model1.setNormRange("fitRangeLeft,fitRangeRight")
rooFitResult = data_model1.fitTo(data, RooFit.Save(), RooFit.Range("fitRangeLeft,fitRangeRight"), RooFit.PrintLevel(-1))
rooFitResult.Print("v")


# Then do extended fit

n_bkg  = RooRealVar("Nbkg","Nbkg", 20, 0, 1000);
exponent = RooRealVar("exponent","exponent", 0, -1., 1.)
data_model = RooExponential("data_model", "data_model", mass, exponent);

data_model_extended = RooExtendPdf("data_model_extended","data_model_extended",data_model,n_bkg) ;

data_model_extended.setNormRange("fitRangeLeft,fitRangeRight")
rooFitResult = data_model_extended.fitTo(data, RooFit.Save(), RooFit.Range("fitRangeLeft,fitRangeRight"), RooFit.PrintLevel(-1) )
rooFitResult.Print("v")