code: func (c *sessionConn) Write(b []byte) (int, error) {
  	//set timeout
  	if err := c.conn.SetWriteDeadline(time.Now().Add(c.timeout)); err != nil {
  		return 0, err
  	}
  	n, err := c.conn.Write(b)
  	if err != nil {
  		errLogger.Printf("Connection write error local address %s remote address %s: %s", c.conn.LocalAddr(), c.conn.RemoteAddr(), err)
  		c.isBad = true
  		c.badError = err
  		return n, driver.ErrBadConn
  	}
  	return n, nil
  }
docs: // Write implements the io.Writer interface.