>The reason I did it this way is that there is no particular reason to limit to one item that has the "single" functionality. Most of the time it is used for the size, but RealGalaxy for example uses it for index and id. We don't currently have any classes with two dicts in the "single" list, but I don't see any reason to code away that possibility.

I see, well I'm assuredly all for not coding out future extensibility, thanks for the explanation.