Updates LaserData.

def update(self):
        '''
        Updates LaserData.
        '''
        if self.hasproxy():
            sonarD = SonarData()
            range = 0
            data = self.proxy.getSonarData()

            sonarD.range = data.range
            sonarD.maxAngle = data.maxAngle
            sonarD.minAngle = data.minAngle
            sonarD.maxRange = data.maxRange
            sonarD.minRange = data.minRange


            self.lock.acquire()
            self.sonar = sonarD
            self.lock.release()