etcdserver/api/rafthttp/util.go
func newStreamRoundTripper(tlsInfo transport.TLSInfo, dialTimeout time.Duration) (http.RoundTripper, error) {
	return transport.NewTimeoutTransport(tlsInfo, dialTimeout, ConnReadTimeout, ConnWriteTimeout)
}
func newStreamRoundTripper(tlsInfo transport.TLSInfo, dialTimeout time.Duration) (http.RoundTripper, error) {
	return transport.NewTimeoutTransport(tlsInfo, dialTimeout, ConnReadTimeout, ConnWriteTimeout)
}
// newStreamRoundTripper returns a roundTripper used to send stream requests
// to rafthttp listener of remote peers.
// Read/write timeout is set for stream roundTripper to promptly
// find out broken status, which minimizes the number of messages
// sent on broken connection.