add several utility functions to FlowAggregationSensor
add several utility functions to FlowAggregationSensor

MelvinTo/firewalla,firewalla/firewalla,firewalla/firewalla,MelvinTo/firewalla,firewalla/firewalla,MelvinTo/firewalla,MelvinTo/firewalla,MelvinTo/firewalla,firewalla/firewalla,firewalla/firewalla