Webiny\Component\Security\User\AbstractUser::getUsername PHP Method

    public function getUsername()
    {
        return $this->username;
    }

 /**
  * Stores user data into an array, encrypts it and returns the encrypted string.
  *
  * @param AbstractUser $user Instance of AbstractUser class that holds the pre-filled object from user provider.
  *
  * @return string
  */
 public function encryptUserData(AbstractUser $user)
 {
     // data (we use short syntax to reduce the size of the cookie or session)
     $data = ['u' => $user->getUsername(), 'vu' => $this->tokenRememberMe ? time() + 86400 * 30 : time() + 86400, 'ap' => $user->getAuthProviderName(), 'up' => $user->getUserProviderName()];
     // build and add token to $data
     $token = $this->getCrypt()->encrypt($this->jsonEncode($data), $this->getEncryptionKey());
     $token = urlencode(rtrim($token, '='));
     return $token;
 }