public function generate()
{
$chars = self::CHARS;
$addChars = $this->getOption('addChars');
if ($addChars !== null) {
$chars .= $addChars;
}
$stringShuffle = $this->stringShuffle($chars);
$length = $this->getOption('length');
if ($length !== null) {
$randomString = substr($stringShuffle, 0, $length);
} else {
$randomString = substr($stringShuffle, 0, mt_rand(self::MINLENGTH, self::MAXLENGTH));
}
return $randomString;
}