source/php/Entity/PostManager.php
public function removeEmptyMeta($meta, $post_id)
    {
        foreach ($meta as $key => $value) {
            $meta = get_post_meta($post_id, $key, true);
            if ($meta) {
                delete_post_meta($post_id, $key);
            }
        }
    }
public function removeEmptyMeta($meta, $post_id)
    {
        foreach ($meta as $key => $value) {
            $meta = get_post_meta($post_id, $key, true);
            if ($meta) {
                delete_post_meta($post_id, $key);
            }
        }
    }
Delete meta data from db if it's deleted from API
@param  array $meta    empty meta data fields
@param  int   $post_id post object id
@return void