code: func NewClient(accessKey string, secretKey string) (*Client, error) {
  	if len(accessKey) == 0 || len(secretKey) == 0 {
  		return nil, errors.New("credentials missing")
  	}
  
  	return &Client{
  		accessKey:  accessKey,
  		secretKey:  secretKey,
  		BaseURL:    defaultBaseURL,
  		HTTPClient: &http.Client{},
  	}, nil
  }
docs: // NewClient Creates a new client of NIFCLOUD DNS