None of the constituent sets are iterable

Raise code

                except TypeError:
                    completed = False
            if completed:
                return

        if not completed:
            if not candidates:
                raise TypeError("None of the constituent sets are iterable")
            raise TypeError(
                "The computation had not completed because of the "
                "undecidable set membership is found in every candidates.")

    @staticmethod
    def _handle_finite_sets(args):
        '''Simplify intersection of one or more FiniteSets and other sets'''