public static function getInstance()
 {
     if (!isset(self::$instance)) {
         $class = __CLASS__;
         self::$instance = new $class();
     }
     return self::$instance;
 }
 public function getInsertLogManager()
 {
     $browser = HeatmapBrowserDAOFactory::getInstance()->createDAO("nLogger_heatmap");
     $os = HeatmapOsDAOFactory::getInstance()->createDAO('nLogger_heatmap');
     $resolution = HeatmapResolutionDAOFactory::getInstance()->createDAO('nLogger_heatmap');
     $env = HeatmapEnvDAOFactory::getInstance()->createDAO('nLogger_heatmap');
     $pageinfo = HeatmapPageDAOFactory::getInstance()->createDAO('nLogger_heatmap');
     $coordinates = HeatmapDataDAOFactory::getInstance()->createDAO('nLogger_heatmap');
     $taginfo = HeatmapTagInfoDAOFactory::getInstance()->createDAO('nLogger_heatmap');
     return new HeatmapInsertLogManager($browser, $os, $resolution, $env, $pageinfo, $coordinates, $taginfo);
 }