FOS\UserBundle\Model\UserInterface::getUsernameCanonical PHP Method

    function getUsernameCanonical();

 /**
  * Enforces that the given user will have an username
  * @param \FOS\UserBundle\Model\UserInterface $user
  */
 public function enforceUsername(UserInterface $user)
 {
     $current = $user->getUsernameCanonical();
     if (is_null($current) || strlen($current) == 0) {
         $email = explode('@', $user->getEmailCanonical(), 2);
         $username = $email[0];
         if (!UsernameValidator::isUsernameValid($username)) {
             $username = UsernameValidator::getValidUsername();
         }
         $newUsername = $this->getNextAvailableUsername($username);
         $user->setUsername($newUsername);
         $this->updateCanonicalFields($user);
     }
 }