ToDo: Validate CAM number and Valid Shutter Speed

def __vCmdSetCamShutterSpeed(self, args):
        '''ToDo: Validate CAM number and Valid Shutter Speed'''
        if len(args) == 1:
            for cam in self.camera_list:
                cam.boSetShutterSpeed(int(args[0]))
        elif len(args) == 2:
            cam = self.camera_list[int(args[1])]
            cam.boSetShutterSpeed(int(args[0]))
        else:
            print ("Usage: setCamShutterSpeed SHUTTERVALUE [CAMNUMBER], Shutter value is the devisor in 1/x (only works for values smaller than 1)")