What value should I return in the bottom of my "insertImage" function?

I'm trying to use the asynchronous API function executeAsync of the Cassandra-PHP-Datastax driver whose demonstration is on the following link: https://github.com/datastax/php-driver/tree/master/ features.

Here is what I produced as code:

function insertImage($url, $src, $alt, $title, $description, $keywords, $htmlContentToTxt, $urlClicked, $urlBroken, $lang, $width, $height, $type, $imageExtension, $attr, $providerName, $cmsUsed, $authorName, $authorUrl, $publishedTime, $centroidScore, $graphBasedScore, $scrapeScore, $centroidWeightedScore, $crawledDate) {
    global $con;

    //création de la column Image
    $con->execute("CREATE TABLE IF NOT EXISTS images(siteUrl varchar PRIMARY KEY, imageUrl varchar, alt varchar, title varchar, description varchar, 
                keywords varchar, textFromWebPage varchar, clicks bigint, broken int, site_lang varchar, width_of_image float, 
                height_of_image float, image_type varchar, image_extension varchar, image_attribute varchar, providerName varchar, 
                cmsUsed varchar, authorName varchar, authorUrl varchar, publishedTime timestamp, centroidScore float, 
                graphBasedScore float, scrapeScore float, centroidWeightedScore float, created_date timestamp) WITH caching='ALL';");
    
    // Using a SSTable Attached Secondary Index (SASI) for "LIKE" (https://docs.datastax.com/en/dse/5.1/cql/cql/cql_using/useSASIIndex.html):
    $con->execute("CREATE CUSTOM INDEX images_prefix ON images(siteUrl, alt, title, keywords, description, textFromWebPage) USING 'org.apache.cassandra.index.sasi.SASIIndex'");
    
    $query = $con->prepare("INSERT INTO images(siteUrl, imageUrl, alt, title, description, keywords, textFromWebPage, clicks, broken, site_lang, width_of_image, height_of_image, image_type, image_extension, image_attribute, providerName, cmsUsed, authorName, authorUrl, publishedTime, centroidScore, graphBasedScore, scrapeScore, centroidWeightedScore, created_date)
                            VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");

    $data = array($url, $src, $alt, $title, $description, $keywords, $htmlContentToTxt, $urlClicked, $urlBroken, $lang, $width, $height,
                    $type, $imageExtension, $attr, $providerName, $cmsUsed, $authorName, $authorUrl, $publishedTime, 
                    $centroidScore, $graphBasedScore, $scrapeScore, $centroidWeightedScore, $crawledDate
            );
        
    $futures = array();
                    
    // execute all statements in background
    foreach ($data as $arguments) {
        // $futures[] = $session->executeAsync($statement, array(
        $futures[] = $con->executeAsync($query, array(          // "executeAsync" est utilisé dans "CASSANDRA Asynchronous"
                        'arguments' => $arguments
        ));
    }
                    
    // wait for all statements to complete
    foreach ($futures as $future) {
    // we will not wait for each result for more than 10 seconds. You must ensure that this future has enough time to be executed by calling "Future::get()"
        $future->get(10);
    }
        
}

My problems:

• about the $data variable. On the Cassandra-PHP-Datastax driver link demo above they used a multidimensional array but in my case it's just a simple array that I'm looking to use.

• Since this is my code above is in a function, what value should I return in the bottom of my insertImage function ??? Should I return the array $futures or the variable $future->get(10) ???

Please guide me please.