code: func (cfg *dynamicTLSConfig) SetLeaf(leaf *tls.Certificate) error {
  	cfg.Lock()
  	defer cfg.Unlock()
  	if err := parseLeafX509Cert(leaf); err != nil {
  		return err
  	}
  	cfg.leaf = leaf
  
  	cfg.notify()
  	return nil
  }
docs: // SetLeaf sets a new leaf.