code: def ReadFlowProcessingRequests(self, cursor=None):
      
      query = ("SELECT request, UNIX_TIMESTAMP(timestamp) "
               "FROM flow_processing_requests")
      cursor.execute(query)
  
      res = []
      for serialized_request, ts in cursor.fetchall():
        req = rdf_flows.FlowProcessingRequest.FromSerializedString(
            serialized_request)
        req.timestamp = mysql_utils.TimestampToRDFDatetime(ts)
        res.append(req)
      return res
docs: Reads all flow processing requests from the database.