code: def ReadMessageHandlerRequests(self, cursor=None):
      
  
      query = ("SELECT UNIX_TIMESTAMP(timestamp), request,"
               "       UNIX_TIMESTAMP(leased_until), leased_by "
               "FROM message_handler_requests "
               "ORDER BY timestamp DESC")
  
      cursor.execute(query)
  
      res = []
      for timestamp, request, leased_until, leased_by in cursor.fetchall():
        req = rdf_objects.MessageHandlerRequest.FromSerializedString(request)
        req.timestamp = mysql_utils.TimestampToRDFDatetime(timestamp)
        req.leased_by = leased_by
        req.leased_until = mysql_utils.TimestampToRDFDatetime(leased_until)
        res.append(req)
      return res
docs: Reads all message handler requests from the database.