public static function select($select)
    {
        if (gettype($select)=="array") {
            foreach ($select as $key => $field) {
                if ($field instanceof Key) {
                    $alias =  '"'.$field.'"';
                    $field =  self::field($field);
                    $select[$key] = "{$field} as {$alias}";
                }
            }
            $select = implode(", ", $select);
        } elseif (gettype($select)!="string") {
            throw new ClusterpointException("\"->select()\" function: passed parametr is not in valid format.", 9002);
        }
        return $select;
    }