/**
* Return a random string made of lowercase letters, uppercase letters and digits
*
* @param number $length The length of the string to get
* @return string
*/
public static function get_alphanumeric_random_string($length = 10)
{
return StringTool::get_random_string($length, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890');
}
