private static void AddFormat(MDocCommand self, Dictionary <string, List <string> > d, string format, string file)
{
if (format == null)
{
self.Error("No format specified.");
}
List <string> l;
if (!d.TryGetValue(format, out l))
{
l = new List <string> ();
d.Add(format, l);
}
l.Add(file);
}