TEST: covering all branches of compute_masked_class_stats functions
TEST: covering all branches of compute_masked_class_stats functions

FrancoisRheaultUS/dipy,matthieudumont/dipy,rfdougherty/dipy,sinkpoint/dipy,beni55/dipy,villalonreina/dipy,jyeatman/dipy,JohnGriffiths/dipy,StongeEtienne/dipy,FrancoisRheaultUS/dipy,StongeEtienne/dipy,mdesco/dipy,jyeatman/dipy,oesteban/dipy,nilgoyyou/dipy,mdesco/dipy,oesteban/dipy,demianw/dipy,matthieudumont/dipy,villalonreina/dipy,Messaoud-Boudjada/dipy,nilgoyyou/dipy,JohnGriffiths/dipy,sinkpoint/dipy,demianw/dipy,Messaoud-Boudjada/dipy,beni55/dipy,rfdougherty/dipy