code: func (c *Client) AddValueDescriptor(v contract.ValueDescriptor) (id string, err error) {
  	conn := c.Pool.Get()
  	defer conn.Close()
  
  	if v.Id != "" {
  		_, err = uuid.Parse(v.Id)
  		if err != nil {
  			return "", db.ErrInvalidObjectId
  		}
  	}
  	return addValue(conn, v)
  }
docs: // ************************** VALUE DESCRIPTOR FUNCTIONS ***************************
  // Add a value descriptor
  // 409 - Formatting is bad or it is not unique
  // 503 - Unexpected
  // TODO: Check for valid printf formatting