def savedoc(self):
        # write output
        if self.dest_file not in None:
            # use stdout if no filename given
            self.document.save('-')
        else:
            self.document.save(self.dest_file)
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/tablib-0.10.0/tablib/packages/odf3/userfield.py/UserFields.savedoc/operator `is` -> `not in`