code: def serve(barFeed, strategyParameters, address, port, batchSize=200):
      """Executes a server that will provide bars and strategy parameters for workers to use.
  
      :param barFeed: The bar feed that each worker will use to backtest the strategy.
      :type barFeed: :class:`pyalgotrade.barfeed.BarFeed`.
      :param strategyParameters: The set of parameters to use for backtesting. An iterable object where **each element is a tuple that holds parameter values**.
      :param address: The address to listen for incoming worker connections.
      :type address: string.
      :param port: The port to listen for incoming worker connections.
      :type port: int.
      :param batchSize: The number of strategy executions that are delivered to each worker.
      :type batchSize: int.
      :rtype: A :class:`Results` instance with the best results found or None if no results were obtained.
      """
  
      paramSource = base.ParameterSource(strategyParameters)
      resultSinc = base.ResultSinc()
      s = xmlrpcserver.Server(
          paramSource,
          resultSinc,
          barFeed,
          address,
          port,
          batchSize=batchSize,
      )
      logger.info("Starting server")
      s.serve()
      logger.info("Server finished")
  
      ret = None
      bestResult, bestParameters = resultSinc.getBest()
      if bestResult is not None:
          logger.info(
              "Best final result %s with parameters %s"
              % (bestResult, bestParameters.args)
          )
          ret = Results(bestParameters.args, bestResult)
      else:
          logger.error(
              "No results. All jobs failed or no jobs were processed."
          )
      return ret
  
file_path: pyalgotrade/pyalgotrade/optimizer/server.py
imports: import pyalgotrade.logger
  from pyalgotrade.optimizer import base
  from pyalgotrade.optimizer import xmlrpcserver
label_desc: Use image node_id 1 for calling a global function with example usage: serve(barFeed, strategyParameters, address, port, batchSize) and returns: ret