code: func (c Conn) CloseWrite() error {
  	if cw, ok := c.Wire.(interface {
  		CloseWrite() error
  	}); ok {
  		return cw.CloseWrite()
  	}
  	return errors.New("pinned: underlying connection does not support CloseWrite")
  }
docs: // CloseWrite shuts down the writing side of the connection.