wp_gdsr_multi_review_average($multi_set_id = 0, $post_id = 0, $echo = true)
- $set_id: id of the multi rating set.
- $post_id: id of the post rating will be attributed to.
- $echo: echo results or return it as a string.
Renders single rating stars image with average rating for the multi rating review.
Function returns: string html with rendered contents.