code: def start(self):
          
  
          if self.log_filename:
              print('Output will be logged to `%s`.' % self.log_filename)
  
          start_time = time.strftime(self.timestamp_fmt)
          print('Started %s' % start_time)
  
          if self.log_filename:
              orig_stdout = sys.stdout
              orig_stderr = sys.stderr
  
              sys.stdout = self.log_file
              sys.stderr = self.log_file
  
              print('Started %s' % start_time)
  
          doit_main = DoitMain(self)
          doit_main.run(['run'])
  
          stop_time = time.strftime(self.timestamp_fmt)
  
          if self.log_filename:
              print('Stopped %s' % stop_time)
              print()
  
              sys.stdout = orig_stdout
              sys.stderr = orig_stderr
              self.log_file.close()
  
          print('Stopped %s' % stop_time)
docs: Begin executing tasks.