rosnodejs get private param

I've written a ROS node using rosnodejs, and I would like to pass it a privately scoped parameter on the command line like: rosrun mynode myscript.js _myparam:=foo What would be as simple as rospy.getParam('~myparam') in rospy seems to not work in rosnodejs. What is the correct way to get a private parameter using rosnodejs?