How to add external monitor variables via iControl API?

I am automating the configuration of an external monitor using the Java iControl API. I can update existing variables using:

 

interfaces.getLocalLBMonitor().set_template_user_defined_string_property();

 

But if this call is used on a variable that doesn't exist it throws this exception:

 

Exception caught in LocalLB::urn:iControl:LocalLB/Monitor::set_template_user_defined_string_property() Exception: Common::OperationFailed primary_error_code : 16908342 (0x01020036) secondary_error_code : 0 error_string : 01020036:3: The requested monitor parameter (/Common/test 1 RECV1=) was not found.

 

Is there a way to add a new variable to an external monitor via the iControl API?