code: func (r FutureDebugLevelResult) Receive() (string, error) {
  	res, err := receiveFuture(r)
  	if err != nil {
  		return "", err
  	}
  
  	// Unmashal the result as a string.
  	var result string
  	err = json.Unmarshal(res, &result)
  	if err != nil {
  		return "", err
  	}
  	return result, nil
  }
docs: // Receive waits for the response promised by the future and returns the result
  // of setting the debug logging level to the passed level specification or the
  // list of of the available subsystems for the special keyword 'show'.