code: func (c *Conn) Set(key string, value []byte) error {
  	code, body, err := c.doREST("PUT", key, value)
  	if err != nil {
  		return err
  	}
  	if code != 201 {
  		return &Error{string(body), code}
  	}
  
  	return nil
  }
docs: // Set stores the data at key