Search for property whose value is not empty

Hi,

I have a requirement, where I need to return the nodes, that contains 2 properties, ex: Make and Model.

In my node structure, there are cases, where make and model properties are available, but Model dont have any value in it.

the property.operation: exists will check if the property itself is exists or not.

How can I check if the property value is not empty?

I am using querybuilder.