public function setProgressChunk(ProgressChunk $chunk_size)
 {
     $this->progressChunk = $chunk_size->getProgressChunk();
 }
<?php

include '../bootstrap.php';
try {
    $instance = new interact();
    $instance->debug = true;
    $instance->intitializeSoapClient($config_file['location']['wsdl'], $config_file['location']['endpoint']);
    if ($instance->login($config_file['auth_regular']['login'], $config_file['auth_regular']['pass'])) {
        $campaign_object = new InteractObject();
        $campaign_object->setFolderName("Mason");
        $campaign_object->setObjectName("masonCampaign_promo");
        $progressChunk = new ProgressChunk();
        $progressChunk->setProgressChunk($progressChunk::CHUNK_10K);
        $preferences = new LaunchPreferences();
        $preferences->setEnabledLimit(false);
        // Enabled limit on recipients
        $preferences->setEnableNthSampling(true);
        $preferences->setEnableProgressAlerts(true);
        $preferences->setProgressChunk($progressChunk);
        $preferences->setProgressEmailAddresses("*****@*****.**");
        //$preferences->setRecipientLimit( 1 ); // Limit to only one recipient, good for testing.
        $preferences->setSamplingNthInterval(1);
        $preferences->setSamplingNthOffset(1);
        $preferences->setSamplingNthSelection(1);
        //$proof_options = new ProofLaunchOptions();
        /*
         * To send a proof instead of real message set proof params ( to entire proof list or specified proof email address ) 
         * or leave empty to send live campaign
         * 
        
        $proof_launch_type = new ProofLaunchType();