def version(self) -> int:
        """Get the experiment version.

        Returns:
            The experiment version if specified else the next version.
        """
        if self._version is None:
            self._version = self._get_next_version()
        return self._version
Get the experiment version.

        Returns:
            The experiment version if specified else the next version.
        
instant-nsr-pl/utils/callbacks.py