def _get_field_stats_dates(self, field='@timestamp'):
        """
        Add indices to `index_info` based on the value the stats api returns,
        as determined by `field`

        :arg field: The field with the date value.  The field must be mapped in
            elasticsearch as a date datatype.  Default: ``@timestamp``
        """
        self.loggit.debug('Getting index date from field_stats API')
        self.loggit.info(
            'Cannot use field_stats on closed indices.  '
            'Omitting any closed indices.'
        )
        self.filter_closed()
        index_lists = chunk_index_list(self.indices)
        for l in index_lists:
            working_list = self.client.field_stats(
                index=to_csv(l), fields=field, level='indices'
                )['indices']
            if working_list:
                for index in list(working_list.keys()):
                    try:
                        s = self.index_info[index]['age']
                        wl = working_list[index]['fields'][field]
                        # Use these new references to keep these lines more
                        # readable
                        s['min_value'] = fix_epoch(wl['min_value'])
                        s['max_value'] = fix_epoch(wl['max_value'])
                    except __HOLE__ as e:
                        raise ActionError(
                            'Field "{0}" not found in index '
                            '"{1}"'.format(field, index)
                        )
dataset/ETHPy150Open elastic/curator/curator/indexlist.py/IndexList._get_field_stats_dates