Making sure the results of  are in the right order

I'm using a `dict` instead of a `list` for `ctx['rv']` in the get callback; I do this because I want to reorder the values in case they arrive in a different order. The problem I see is that of  duplicated keys, cause they'll overwrite the result in the dictionary. I don't know if it's possible for a value to change during a get operation, I guess it is (e.g. `get (key1, ..., keyN, key1) -->  [value1, ..., valueN, changedValue1]` if someone sets it during the get op), but I don't see this as a major problem.  I'm a bit concerned about the extended mode where the tuple containing `cas` will be overwritten, but on the other hand, the same happens when you  do a `dict( ctx['rv'] )`...