code: def write_log(self, fs=None):
          
          log = StringIO.StringIO()
          log.write(self.setup_src)
  
          # If the function is not bound, write the test score to the log
          if not self.is_class_method:
              time_avg = convert_time_units(self.time_average_seconds)
              log.write("\nAverage time: {0} \n".format(time_avg))
  
          if fs:
              with open(fs, 'w') as _f:
                  _f.write(log.getvalue())
docs: Write the results of the benchmark to a log file.
          :param fs: file-like object.