AEM SDK - Container - Limit number elements to add

Hi all!

I have a component "ModuleComponent" and it has a container where user add another component "CardComponent". Container only allows "CardComponent" but I do not know how to limit number of components to add.  Anyone knows a possible control? I have thought to use a listener (refresh page - when children is added for example) on container module, but I can not how to implement it. 

Any ideas? Thanks for your time!