code: func (c *Client) initPrefix() error {
  	c.isSharePrefix = false
  	root := c.discoRoot()
  	u, err := url.Parse(root)
  	if err != nil {
  		return err
  	}
  	if len(u.Path) > 1 {
  		c.prefixv = strings.TrimRight(root, "/")
  		return nil
  	}
  	return c.condDiscovery()
  }
docs: // initPrefix uses the user provided server URL to define the URL
  // prefix to the blobserver root. If the server URL has a path
  // component then it is directly used, otherwise the blobRoot
  // from the discovery is used as the path.