Convert to pandas MultiIndex.

        Returns
        -------
        pandas.base.MultiIndex

def to_pandas(self):
        """Convert to pandas MultiIndex.

        Returns
        -------
        pandas.base.MultiIndex

        """
        if not all(ind.is_raw() for ind in self.values):
            raise ValueError('Cannot convert to pandas MultiIndex if not evaluated.')

        from pandas import MultiIndex as PandasMultiIndex

        arrays = [ind.values for ind in self.values]

        return PandasMultiIndex.from_arrays(arrays, names=self.names)