code: def is_all_field_none(self):
          
  
          if self._id_ is not None:
              return False
  
          if self._created is not None:
              return False
  
          if self._updated is not None:
              return False
  
          if self._invoice_date is not None:
              return False
  
          if self._invoice_number is not None:
              return False
  
          if self._status is not None:
              return False
  
          if self._group is not None:
              return False
  
          if self._total_vat_inclusive is not None:
              return False
  
          if self._total_vat_exclusive is not None:
              return False
  
          if self._total_vat is not None:
              return False
  
          if self._alias is not None:
              return False
  
          if self._address is not None:
              return False
  
          if self._counterparty_alias is not None:
              return False
  
          if self._counterparty_address is not None:
              return False
  
          if self._chamber_of_commerce_number is not None:
              return False
  
          if self._vat_number is not None:
              return False
  
          if self._request_reference_split_the_bill is not None:
              return False
  
          return True
docs: :rtype: bool