def _nextPage(self, offset):
        """Retrieves the next set of results from the service."""
        self.logger.debug("Iterator crecord=%s" % str(self.crecord))
        params = {
            'q': self.q,
            'start': str(offset),
            'rows': str(self.pagesize),
            'fl': self.fields,
            'explainOther': '',
            'hl.fl': '',
        }
        if self.fq is not None:
            params['fq'] = self.fq
        self.res = self.client.search(params)
        self._numhits = int(self.res['response']['numFound'])