public static void SerialisoiXml(string tiedosto, Harjoitukset ic)
 {
     XmlSerializer xs = new XmlSerializer(ic.GetType());
     TextWriter tw = new StreamWriter(tiedosto);
     try
     {
         xs.Serialize(tw, ic);
     }
     catch (Exception e)
     {
         throw e;
     }
     finally
     {
         tw.Close();
     }
 }