code: def _validate_empty_attributes(self, attributes):
          
          attrs_to_check = set(self._required) & set(attributes)
          for attr in attrs_to_check:
              value = getattr(self, attr)  # We should always have a value here
              if value is None or value == "":
                  raise ValueError(
                      "Attribute %s cannot be None or an empty string since it is required." % attr
                  )
docs: Check that required attributes are not empty.