code: def setup_config(self, cfg=None):
          '''
          Open suitable config file.
          :return:
          '''
          _opts, _args = optparse.OptionParser.parse_args(self)
          configs = self.find_existing_configs(_opts.support_unit)
          if configs and cfg not in configs:
              cfg = configs[0]
  
          return config.master_config(self.get_config_file_path(cfg)f setup_config(self, cfg=None):
          '''
          Open suitable config file.
          :return:
          '''
          _opts, _args = optparse.OptionParser.parse_args(self)
          configs = self.find_existing_configs(_opts.support_unit)
          if configs and cfg not in configs:
              cfg = configs[0]
  
          return config.master_config(self.get_config_file_path(cfg))
docs: Open suitable config file.
          :return: