def poll(self):
        """Check if child process has terminated. Set and return returncode attribute."""
        if self._worker is None:
            self.returncode = None
            return self.returncode
        elif self._worker.is_alive():
            self.returncode = None
            return self.returncode
        else:
            self.returncode = self._worker.state.return_value
            return self.returncode
Check if child process has terminated. Set and return returncode attribute.
lib/mlpatches/modules/subprocess.py