QueryMonitor::init PHP Method

    public static function init($file = null)
    {
        static $instance = null;
        if (!$instance) {
            $instance = new QueryMonitor($file);
        }
        return $instance;
    }

/**
 * Require the plugin files for Query Monitor, faking a
 * plugin activation, if it's the first time.
 */
function wpcom_vip_qm_require()
{
    /**
     * Filter whether Query Monitor is activated; return true,
     * if QM should be activated.
     *
     * @param bool $enable False by default
     */
    if (!apply_filters('wpcom_vip_qm_enable', false)) {
        return;
    }
    if (!defined('SAVEQUERIES')) {
        define('SAVEQUERIES', true);
    }
    // For hyperdb, which doesn't use SAVEQUERIES
    global $wpdb;
    $wpdb->save_queries = SAVEQUERIES;
    $wpcom_vip_qm_file = __DIR__ . '/query-monitor/query-monitor.php';
    require_once $wpcom_vip_qm_file;
    // Because we're including Query Monitor as an MU plugin, we need to
    // manually call the `activate` method on `activation`.
    if (0 === get_option('wpcom_vip_qm_activated', 0)) {
        QueryMonitor::init($wpcom_vip_qm_file)->activate(true);
        update_option('wpcom_vip_qm_activated', 1, true);
    }
    // We don't want to share our environment information via Query Monitor
    remove_filter('qm/collectors', 'register_qm_collector_environment', 20, 2);
    // We know we haven't got the QM DB drop-in in place, so don't show the message
    add_filter('qm/show_extended_query_prompt', '__return_false');
}