// To use a custom dialer or TLS config and still attempt HTTP/2
	// upgrades, set this to true.
	ForceAttemptHTTP2 bool
}

func (t *Transport) writeBufferSize() int {
	if t.WriteBufferSize > 0 {
		return t.WriteBufferSize
	}
	return 4 << 10
}

func (t *Transport) readBufferSize() int {
	if t.ReadBufferSize > 0 {
		return t.ReadBufferSize
	}
	return 4 << 10
}