docs: public PropertyOwner retrieveUserProperties(String strRegistrationKey)
      {
          if (this.getTask() != null)
          {
              if (this.getTask() instanceof PropertyOwner)
                  return ((PropertyOwner)this.getTask()).retrieveUserProperties(strRegistrationKey);  // Try task
              if (this.getTask().getApplication() != null)
                  return this.getTask().getApplication().retrieveUserProperties(strRegistrationKey);  // Try app
          }
          return null;    // Not found
      }