func FlushPeriod(p time.Duration) Option {
	return Option(func(c *config) {
		c.Conn.FlushPeriod = p
	})
}
func FlushPeriod(p time.Duration) Option {
	return Option(func(c *config) {
		c.Conn.FlushPeriod = p
	})
}
// FlushPeriod sets how often the Client's buffer is flushed. If p is 0, the
// goroutine that periodically flush the buffer is not lauched and the buffer
// is only flushed when it is full.
//
// By default, the flush period is 100 ms.  This option is ignored in
// Client.Clone().