public function __construct($email = null)
{
$this->email = $email;
$this->created = $this->updated = new \DateTime();
$this->groups = new ArrayCollection();
$this->attributes = new ArrayCollection();
$this->identities = new ArrayCollection();
$this->clients = new ArrayCollection();
$this->role = new Role();
$this->is_admin = false;
$this->is_public = false;
$this->setPassword($this->generateRandomString(6));
// make sure password is not empty
$this->points = 0;
}