public SsdpDiscover(string endpointIp, int endpointPort)
{
RequestBuilder.Append(
$@"M-SEARCH * HTTP/1.1
Host: {endpointIp}:{endpointPort}
Content-Length: 0
MAN: ""ssdp:discover""
MX: 2
ST: urn:schemas-upnp-org:device:MediaRenderer:1
");
}