code: def config_file(self, filename):
          
          if os.path.isfile(filename):
              with open(filename, 'r') as fh:
                  self._config_data = json.load(fh)
          else:
              self.tcex.log.error('Could not load configuration file "{}".'.format(filename))
docs: Load configuration data from provided file and inject values into sys.argv.
  
          Args:
              config (str): The configuration file name.