def dropna(self):
        """Returns MultiIndex without any rows containing null values according to Baloo's convention.

        Returns
        -------
        MultiIndex
            MultiIndex with no null values.

        """
        not_nas = [v.notna() for v in self.values]
        and_filter = reduce(lambda x, y: x & y, not_nas)

        return self[and_filter]
Returns MultiIndex without any rows containing null values according to Baloo's convention.

        Returns
        -------
        MultiIndex
            MultiIndex with no null values.