Returns last Bumper. 

        @return last JdeRobotTypes Bumper saved

def getBumper(self):
        '''
        Returns last Bumper. 

        @return last JdeRobotTypes Bumper saved

        '''
        if self.hasproxy():
            self.lock.acquire()
            bumper = self.bumper
            self.lock.release()
            return bumper

        return None