A method for detecting a malicious node in a network. The restrictor includes a restrictor body positioned on a top sheet of a stack of sheet materials which are positioned in a dispenser. A first section extends vertically between the window opening and the door opening, a second section extends vertically between the window opening and the door opening, and a third section of a width substantially equal to that of the window opening extends under the window opening. The treadbase also includes a magnetic braking assembly for regulating the speed of the endless belt to prevent the endless belt from moving at a rate that is faster than the rate at which the treadbase motor is driving the endless belt. A spiral power spring is connected between the housing and the reel.