// Displays the header information that accompanied a request.
public static void DisplayWebHeaderCollection(HttpListenerResponse response)
{
    WebHeaderCollection headers = response.Headers;
    // Get each header and display each value.
    foreach (string key in headers.AllKeys)
    {
        string[] values = headers.GetValues(key);
        if(values.Length > 0) 
        {
            Console.WriteLine("The values of the {0} header are: ", key);
            foreach (string value in values) 
            {
                Console.WriteLine("   {0}", value);
            }
        }
        else
        {
            Console.WriteLine("There is no value associated with the header.");
        }
    }
}