def _check_exception(self):
        """if there's a saved exception, raise & clear it"""
        if self._saved_exception is not None:
            x = self._saved_exception
            self._saved_exception = None
            raise x
def _check_exception ( self ) : if self . _saved_exception is not None : x = self . _saved_exception self . _saved_exception = None raise x
if there's a saved exception, raise & clear it