Bliz. unit frames are configured using the
UnitFrame_Initialize function. If the unit has a myHealPredictionBar, it gets passed to this function as one of it's parameters which is assigned to:
Code:
self.myHealPredictionBar = myHealPredictionBar
When called, the
UnitFrameHealPredictionBars_Update function checks if the frame has a .myHealPredictionBar and if so, updates it.