func (p *proxyALRobotPosture) GoToPosture(postureName string, maxSpeedFraction float32) (bool, error) {
    var ret bool
    args := bus.NewParams("(sf)", postureName, maxSpeedFraction)
    resp := bus.NewResponse("b", &ret)
    err := p.Proxy().Call2("goToPosture", args, resp)