code: func (c *Collection) DeleteAll() (int, error) {
  	t := c.pool.NewTransaction()
  	count := 0
  	t.DeleteAll(c, &count)
  	if err := t.Exec(); err != nil {
  		return count, err
  	}
  	return count, nil
  }
docs: // DeleteAll deletes all the models of the given type in a single transaction. See
  // http://redis.io/topics/transactions. It returns the number of models deleted
  // and an error if there was a problem connecting to the database.