Testing is an essential component of development and design. We have created a simple test in a WFD to confirm the values we are computing are correct. In this WFD some sample input data is been created in the Script Data Input.  

Here you can see there are two variable in Int format, named Var0 and Var1. To add this following script is used:

The new variable is created here as Total1, in this variable the script is implemented.
The script will only add the value of those variable which has same name here mentioned as Var0 and Var1(you can change the variable name according to your requirement but the name which you put should be same differentiating with 0,1,2,3,4….. after the name of the variable. Variable Total1 will show the total sum of Var0 and Var1.

‍