How to check if gradients of custom criterions are computed correctly?

[Synchro]

Hey, just as the title say. 
Is there a common test module to check if the gradient of a custom loss are actually coherents? 

Thank you in advance 

[Vislab]

The test.lua file has alot of examples of how to test your criterion. See this MSECriterion example

[Synchro]

Yep, apparently I didn't turn on notifications for this post but I found that out later that day and I forgot to answer. 
I wrote multiple tests for custom criterions just using the exact same way.  

Thank you for the link anyway! A hi from Bologna across the region. :)