code: public static function getSyncOptions($optionName, $individualSyncOptions = null) {
          //try object specific settings
          if ($individualSyncOptions != null &&
              is_array($individualSyncOptions) &&
              array_key_exists($optionName, $individualSyncOptions))
          {
              return $individualSyncOptions[$optionName];
          }
          
          //try yii2 params
          else if (isset(Yii::$app->params['LDAP-User-Sync-Options']) &&
              is_array(Yii::$app->params['LDAP-User-Sync-Options']) &&
              array_key_exists($optionName, Yii::$app->params['LDAP-User-Sync-Options']))
          {
              return Yii::$app->params['LDAP-User-Sync-Options'][$optionName];
          }
          
          //default from distribution
          else if (array_key_exists($optionName, static::SYNC_OPTIONS_TEMPLATE_WITHOUT_BACKEND_TASK)) {
              return static::SYNC_OPTIONS_TEMPLATE_WITHOUT_BACKEND_TASK[$optionName];
          }
          
          //Exception
          else {
              throw new \yii\base\Exception('Sync-option ' . $optionName . ' not found. Please define settings in the config/params.php of the yii2 framework as described on top of the UserDbLdap.php');   
          }
      }
docs: Get a value of the synchronisation options by option key.
  The options can be defined with the setIndividualSyncOptions
  function of this class for a single object, or global in the yii2 params.php.
  If nothing is defined the defaults from the varibale SYNC_OPTIONS_TEMPLATE_WITHOUT_BACKEND_TASK
  are used.
  
  @param string $optionName The option key of the value to retrive.
  @param string $individualSyncOptions Array with individual sync options for this function call only
  @return mixed The value of the option key
  @throws \yii\base\Exception if option key is not found in the given option set.