This decides which path should be taken at a “fork in the road” based on if a variable is present (filled). For this, one possible transition must be designated as false (not available, empty), and the other designated as true (available, filled).
This handler is placed directly on an XOR-decision.

com.dooris.bpm.actionhandler.VariableExistsDecisionHandler

any

any

-

Here, the name of the variable used to choose the path is entered.