code: def _query(self, resource_id, max_rows):
          
          from astropy.io.votable import parse_single_table
  
          if max_rows is not None and max_rows >= 0:
              max_rows_str = str(max_rows)
          else:
              max_rows_str = str(9999999999)
  
          tmp_moc = tempfile.NamedTemporaryFile(delete=False)
  
          self.write(tmp_moc.name)
          r = requests.post('http://cdsxmatch.u-strasbg.fr/QueryCat/QueryCat',
                            data={'mode': 'mocfile',
                                  'catName': resource_id,
                                  'format': 'votable',
                                  'limit': max_rows_str},
                            files={'moc': open(tmp_moc.name, 'rb')},
                            headers={'User-Agent': 'MOCPy'},
                            stream=True)
  
          tmp_vot = BytesIO()
          tmp_vot.write(r.content)
  
          table = parse_single_table(tmp_vot).to_table()
  
          # finally delete temp files
          os.unlink(tmp_moc.name)
  
          return table
docs: Internal method to query Simbad or a VizieR table
          for sources in the coverage of the MOC instance