private static string GenerateSignature(this IUserSession session, string signingKey, string baseString, string tokenSecret)
{
session.PlatformAdaptor.AssignKey(Encoding.UTF8.GetBytes(string.Format("{0}&{1}", OAuthUrlEncode(signingKey),
string.IsNullOrEmpty(tokenSecret)
? ""
: OAuthUrlEncode(tokenSecret))));
var dataBuffer = Encoding.UTF8.GetBytes(baseString);
var hashBytes = session.PlatformAdaptor.ComputeHash(dataBuffer);
var signatureString = Convert.ToBase64String(hashBytes);
return signatureString;
}