Check for the existence of Instance in Revit project

Hello everyone,
I am trying to create an if path that checks the existence of an instance and update the parameters if it exists. It will be in a larger file that is creating massing objects from an excel sheet. I’m thinking I can just a the if path before the “FamilyInstance.bypointandlevel” node. If the components exist I would just bypass the node. This is where I want to add the if statement.

I can figure out the “if” node. I cant find a node or series of nodes that checks for the existences of an Instance. Can anyone send me in the right direction?


The node you’re looking for is called “All Elements of Family Type”