FluidTYPO3\Vhs\ViewHelpers\Once\InstanceViewHelper::storeIdentifier PHP Method

    protected function storeIdentifier()
    {
        $index = get_class($this);
        $identifier = $this->getIdentifier();
        if (false === is_array($GLOBALS[$index])) {
            $GLOBALS[$index] = [];
        }
        $GLOBALS[$index][$identifier] = true;
    }