public function material()
    {
        if (is_null($this->material)) {
            $this->material = new Material($this->accessToken);
        }

        return $this->material;
    }
public function material()
    {
        if (is_null($this->material)) {
            $this->material = new Material($this->accessToken);
        }

        return $this->material;
    }
Return the material instance.

@return \EasyWeChat\ShakeAround\Material