code: func (c *Collection) Save(model Model) error {
  	t := c.pool.NewTransaction()
  	t.Save(c, model)
  	if err := t.Exec(); err != nil {
  		return err
  	}
  	return nil
  }
docs: // Save writes a model (a struct which satisfies the Model interface) to the
  // redis database. Save returns an error if the type of model does not match the
  // registered Collection. To make a struct satisfy the Model interface, you can
  // embed zoom.RandomID, which will generate pseudo-random ids for each model.