How to check if an object is a child (Similar behavior of instance of from Java)

[tmiwata]

For example I have 3 object.

  1. Parent Obj
  2. Child Obj = ref object of Parent Obj
  3. secondChild Obj



proc getProcess*(): Parent Obj =
    

if process1
    return Child Obj
if process2
    return secondChild Obj

and so on..

Question: I want to check if the getProcess returned object is Child Obj, 
Because when I'm trying to check in unit testing it always says its Parent Obj. 
I just want to know if there is same as instance of from Java, to check its 
reference.

FYI: I am using Testament.