How to find out which subsystem is Stateflow using M script?

I want to find out which subsystem is Stateflow using M-Script. In Matlab 2010b we can find out which subsystem is stateflow using some commands, but same commands did not work in Matlab 2013b. Can any one please give me an alternative solution that will work for both matlab 2010b and 2013b.

Code: In 2010b (Select any Stateflow from model)

>> a = get(gcbh)

>> a.MaskType

ans =

Stateflow

Code: In 2013b( Select any Stateflow from model)

>> a = get(gcbh)

>> a.MaskType

ans =

     ''