code: def _process_params(self):
          
          # transform sort dict into str
          self._sort_to_str()
  
          if 'rows' not in self._solr_params:
              self._solr_params['rows'] = self._cfg['row_size']
  
          for key, val in self._solr_params.items():
              if isinstance(val, str) and six.PY2:
                  self._solr_params[key] = val.encode(encoding='UTF-8')
          return self._solr_params
docs: Adds default row size if it's not given in the query.
          Converts param values into unicode strings.
  
          Returns:
              Processed self._solr_params dict.