def to_regular_arrays(self, array):
        """
        Expands from an array of type `self.dtype` into a list of
        arrays with dtypes corresponding to the factor domains.

        :param np.ndarray array: An `np.array` of type `self.dtype`.

        :rtype: ``list``
        """
        return separate_struct_array(self._mytype(array), self._dtypes)