code: func (c *Client) CreateCheckoutKey(account, repo, keyType string) (*CheckoutKey, error) {
  	checkoutKey := &CheckoutKey{}
  
  	body := struct {
  		KeyType string `json:"type"`
  	}{KeyType: keyType}
  
  	err := c.request("POST", fmt.Sprintf("project/%s/%s/checkout-key", account, repo), checkoutKey, nil, body)
  	if err != nil {
  		return nil, err
  	}
  
  	return checkoutKey, nil
  }
docs: // CreateCheckoutKey creates a new checkout key for a project
  // Valid key types are currently deploy-key and github-user-key
  //
  // The github-user-key type requires that the API token being used be a user API token