code: def is_all_field_none(self):
          
  
          if self._status is not None:
              return False
  
          if self._balance_preferred is not None:
              return False
  
          if self._balance_threshold_low is not None:
              return False
  
          if self._method_fill is not None:
              return False
  
          if self._issuer is not None:
              return False
  
          return True
docs: :rtype: bool