How to compute errors on a "createIntegral" instance?

Dear Experts,
can you please tell me how to compute the errors on a “createIntegral” ?

RooAbsReal* EffPDFintegral = EffPDFgoodTag->createIntegral(…);
double integralValue = EffPDFintegral->getVal();
double integralError = EffPDFintegral->???; // ### what shall I put here ? ###

Many thanks,

  • Mauro.