public function loadFromString($string)
    {
        $target = array();
        $array = explode(self::SEPARATOR, $string);

        foreach ($array as $index => $value) {
            // Additional check
            if (!empty($value)) {
                // Ensure we have only clean values
                if (strpos(self::SEPARATOR, $value) === false) {
                    array_push($target, $value);
                }
            }
        }

        // Override with modified one
        $this->collection = $target;
    }