code: def is_all_field_none(self):
          
  
          if self._time_start is not None:
              return False
  
          if self._time_end is not None:
              return False
  
          if self._recurrence_unit is not None:
              return False
  
          if self._recurrence_size is not None:
              return False
  
          if self._status is not None:
              return False
  
          if self._object_ is not None:
              return False
  
          return True
docs: :rtype: bool