private static void ValidateGroup(Group group)
        {
            if (group.Name == null) throw new XmlDidNotPassValidationException("Group Name is missing.");

            foreach (var command in group.Commands)
            {
                if (command.Source == null)
                    throw new XmlDidNotPassValidationException(string.Format("Command Source is missing in Group {0}.",
                                                                             group.Name));
                if (command.Destination == null)
                {
                    log.DebugFormat(
                        "Destination missing from xml for group '{0}' and source '{1}'.  Using Convention to derive destination",
                        group.Name, command.Source);
                }
            }
        }