public HttpListenerContext GetContext()
{
// The prefixes are not checked when using the async interface!?
if (prefixes.Count == 0)
throw new InvalidOperationException ("Please, call AddPrefix before using this method.");
ListenerAsyncResult ares = (ListenerAsyncResult) BeginGetContext (null, null);
ares.InGet = true;
return EndGetContext (ares);
}