round=qsample(NULLSTR,model,steps=nullsteps)
        explainer = shap.KernelExplainer(funcm_,np.array([s_background]))
        shap_values = explainer.shap_values(X[:shapnum])
        
        self.shap_index=pd.DataFrame(shap_values.mean(axis=0),
                                     columns=[&#39;shap&#39;])\
                          .sort_values(&#39;shap&#39;,
                                       ascending=False).index.values
        
        model.shap_index=self.shap_index

        self.veritas_mode