is_resource

<?php     public function isGdResource()

    {

        if (is_resource($this->data)) {

            return (get_resource_type($this->data) == 'gd');

        }

<?php     public function isStream()

    {

        if ($this->data instanceof StreamInterface) return true;

        if (!is_resource($this->data)) return false;

        if (get_resource_type($this->data) !== 'stream') return false;



        return true;

<?php     {

        $backupName = $this->argument(0)->value();



        if (is_resource($backup = $image->getBackup($backupName))) {




            imagedestroy($image->getCore());