code: func (c *connectionTracker) Close() {
  	c.lock.Lock()
  	defer c.lock.Unlock()
  	for conn := range c.conns {
  		if err := conn.Close(); err != nil {
  			log.WithoutContext().Errorf("Error while closing connection: %v", err)
  		}
  		delete(c.conns, conn)
  	}
  }
docs: // Close close all the connections in the tracked connections list