public function queryAssoc($statement, $params = array()) {
        $start = microtime(true);
        $query = $this->prepare($statement);
        try {
            $query->execute($params);
        } catch (\PDOException $e){
            $this->error($e->getMessage(), array(
                'File' => __FILE__,
                'Line' => __LINE__ - 4,
                'Query' => $statement .'',
                'Params' => $params,
                'Trace' => $e->getTraceAsString()
            ));
            return null;
        }
        $r = $query->fetchAll(\PDO::FETCH_ASSOC);
        $this->debug($statement . '', array(
            'params' => $params,
            'intoArray' => 'assoc',
            'rows' => count($r),
            'time' => microtime(true) - $start,
            'dns' => $this->dns
        ));
        return $r;
    }