code: func (c *Client) SetTimeout(timeout time.Duration) {
  	if timeout == time.Duration(0) {
  		timeout = DefaultTimeout
  	}
  	c.timeout = timeout
  }
docs: // SetTimeout specifies the socket read/write timeout.
  // If zero, DefaultTimeout is used. If < 0, there's
  // no timeout. This method must be called before any
  // connections to the memcached server are opened.