The method 1, wherein the first power management event is {HEAD ~ a power} down event and the second power management event is {TAIL ~ a power} up event 
The method 1 , wherein the first power management event is { HEAD ~ a power } down event and the second power management event is { TAIL ~ a power } up event
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH