isa probability distribution?

How can I check whether variables are probability distributions made by makedist? For example:

x(1) = makedist('Gamma');
x(2) = makedist('Normal');
x(3) = makedist('Exponential');

I want a function like

isa(x(i),'probdist')

that returns true for all three x's. As I understand it, isa would work if these distributions all had a common parent, e.g. called 'probdist', but I can't find any such common parent.

Thanks for any suggestions...

Answer 1

[Eric]

By using

 >> whos

I was able to determine that x's class is a "prob.ToolboxFittableParametricDistribution" object, such that

 for i=1:3
   isa(x(i),'prob.ToolboxFittableParametricDistribution')
 end

returns true for all three x's.