docs: def _add_process_guards(self, engine):
          """Add multiprocessing guards.
  
          Forces a connection to be reconnected if it is detected
          as having been shared to a sub-process.
  
          """
  
          @sqlalchemy.event.listens_for(engine, "connect")
          def connect(dbapi_connection, connection_record):
              connection_record.info['pid'] = os.getpid()
  
          @sqlalchemy.event.listens_for(engine, "checkout")
          def checkout(dbapi_connection, connection_record, connection_proxy):
              pid = os.getpid()
              if connection_record.info['pid'] != pid:
                  self.logger.debug(
                      "Parent process %(orig)s forked (%(newproc)s) with an open database connection, "
                      "which is being discarded and recreated." % {"newproc": pid, "orig": connection_record.info['pid']})
                  connection_record.connection = connection_proxy.connection = None
                  raise exc.DisconnectionError(
                      "Connection record belongs to pid %s, attempting to check out in pid %s" % (
                          connection_record.info['pid'], pid)
                  )