public function setAssociableHotspots(AssociableHotspotCollection $associableHotspots)
    {
        if (count($associableHotspots) > 0) {
            $this->associableHotspots = $associableHotspots;
        } else {
            $msg = "A GraphicGapMatch interaction must be composed of at least 1 AssociableHotspot object, none given.";
            throw new InvalidArgumentException($msg);
        }
    }