etcdserver/api/rafthttp/util.go
func serverVersion(h http.Header) *semver.Version {
	verStr := h.Get("X-Server-Version")
	// backward compatibility with etcd 2.0
	if verStr == "" {
		verStr = "2.0.0"
	}
	return semver.Must(semver.NewVersion(verStr))
}
func serverVersion(h http.Header) *semver.Version {
	verStr := h.Get("X-Server-Version")
	// backward compatibility with etcd 2.0
	if verStr == "" {
		verStr = "2.0.0"
	}
	return semver.Must(semver.NewVersion(verStr))
}
// serverVersion returns the server version from the given header.