code: func (c *Consumer) Close() error {
  	c.connsLock.Lock()
  	defer c.connsLock.Unlock()
  
  	var errStrings []string
  
  	if len(c.conns) == 0 {
  		return errors.New("connection does not exist")
  	}
  	for len(c.conns) > 0 {
  		if err := c.conns[0].close(); err != nil {
  			errStrings = append(errStrings, err.Error())
  		}
  		c.conns = c.conns[1:]
  	}
  
  	if len(errStrings) > 0 {
  		return fmt.Errorf(strings.Join(errStrings, ", "))
  	}
  
  	return nil
  }
docs: // Close terminates all previously opened websocket connections to the traffic
  // controller.  It will return an error if there are no open connections, or
  // if it has problems closing any connection.