/**
  * Get filtered user properties from user provider
  *
  * @static
  * @access public
  * @param  UserProviderInterface $user
  * @return array
  */
 public static function getProperties(UserProviderInterface $user)
 {
     $properties = array('username' => $user->getUsername(), 'name' => $user->getName(), 'email' => $user->getEmail(), 'role' => $user->getRole(), $user->getExternalIdColumn() => $user->getExternalId());
     $properties = array_merge($properties, $user->getExtraAttributes());
     return array_filter($properties, array(__NAMESPACE__ . '\\UserProperty', 'isNotEmptyValue'));
 }