code: func (r *Registrar) QueryRegistration() (*Resource, error) {
  	if r == nil || r.user == nil {
  		return nil, errors.New("acme: cannot query the registration of a nil client or user")
  	}
  
  	// Log the URL here instead of the email as the email may not be set
  	log.Infof("acme: Querying account for %s", r.user.GetRegistration().URI)
  
  	account, err := r.core.Accounts.Get(r.user.GetRegistration().URI)
  	if err != nil {
  		return nil, err
  	}
  
  	return &Resource{
  		Body: account,
  		// Location: header is not returned so this needs to be populated off of existing URI
  		URI: r.user.GetRegistration().URI,
  	}, nil
  }
docs: // QueryRegistration runs a POST request on the client's registration and returns the result.
  //
  // This is similar to the Register function,
  // but acting on an existing registration link and resource.