void UnregisterFunctionReference ( const [FRigVMGraphFunctionIdentifier](API\Plugins\RigVM\RigVMCore\FRigVMGraphFunctionIdentifier) & InFunction, [URigVMFunctionReferenceNode](API\Plugins\RigVMDeveloper\RigVMModel\Nodes\URigVMFunctionReferenceNode) * InReference )