public function add($objectID, $filePath, $caption = '') {
        $imageAsString = $this->encode($filePath);

        $cmdbCategory = new CMDBCategory($this->api);

        $cmdbCategory->create(
            $objectID,
            'C__CATG__IMAGES',
            [
                'name' => $caption,
                'content' => $imageAsString
            ]
        );

        return $this;
    }