def onchange(self, value):
        log.debug('combo box. selected %s' % value)
        self.set_value(value)
        return self.eventManager.propagate(self.EVENT_ONCHANGE, [value])
IRF Sims-Zha error band method 3. Does not assume symmetric error bands around mean.
dataset/ETHPy150Open dddomodossola/remi/remi/gui.py/DropDown.onchange--crossover with--dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/tsa/vector_ar/irf.py/IRAnalysis.err_band_sz3