def fillna(self, series, addition=0):
        """
        Fills with encoder specific default values.

        :param data: examined to determine defaults
        :param addition: uniquely identify this set of fillnas if necessary
        :return: filled data
        """
        if series.dtype == numpy.object:
            return series

        return series.fillna(self.missing_value + addition).astype(self.dtype)
Fills with encoder specific default values.

        :param data: examined to determine defaults
        :param addition: uniquely identify this set of fillnas if necessary
        :return: filled data