public void AddGroup(string groupId)
{
if (Version == 0)
{
throw new InvalidOperationException("Group needs to be started first");
}
if (_groupIds.Contains(groupId))
{
throw new InvalidOperationException("Group already added to region");
}
var e = new GroupAddedToRegion(Id, groupId);
Publish(e);
}
private void When(GroupAddedToRegion e)
{
_groupIds.Add(e.GroupId);
}
