Bolt\Extension\AssetTrait::loadAssets PHP Method

    private function loadAssets()
    {
        if ($this->loadedAssets) {
            return;
        }
        foreach ((array) $this->registerAssets() as $asset) {
            if (!$asset instanceof AssetInterface) {
                throw new \InvalidArgumentException(sprintf('%s::registerAssets() should return a list of Bolt\\Asset\\AssetInterface objects. Got: %s', get_called_class(), is_object($asset) ? get_class($asset) : gettype($asset)));
            }
            $this->addAsset($asset);
        }
        $this->loadedAssets = true;
    }