A method of estimating the output light flux of a light emitting diode, comprises applying a drive current waveform to the LED over a period of time comprising a testing period. A switch at the edge of the MAN encapsulates a data packet in a new header, which is used to specify the customer domain tags. A backrest is associated with the seating surface and is pivotally moveable between an upright position providing back support for a person sitting on the seating surface and a lowered stowed position within the concavity of the seating surface. An overmold integrates the modules of a modular implantable medical device into a single structure. The over-center mechanism is tripped back and forth by a shift disc engaged by a pair of tabs of a turret coupling assembly.