private static Uri ParseProxyUri(string proxyString, bool validate) {
if (validate) {
if (proxyString.Length == 0) {
return null;
}
if (proxyString.IndexOf('=') != -1) {
return null;
}
}
if (proxyString.IndexOf("://") == -1) {
proxyString = "http://" + proxyString;
}
return new Uri(proxyString);
}