[MoveIt!] How to set a start pose with python?

Hi guys, is it possible to set the pose (e.g. described as a list of joint angles) of the robot to certain values without planning a path, using the python move_group interface? Possibly there doesn't exist a path from my current pose A to the desired start pose B, but I want to find a path from B to C. I think the '[set_start_state](http://docs.ros.org/indigo/api/moveit_commander/html/classmoveit__commander_1_1move__group_1_1MoveGroupCommander.html#a20fb40fbc2425e5d308924d9f4bbac6f)' function is supposed to provide this; however, I don't know how the start point is supposed to be specified (as msg).