Knockout includes a function called ko.isObservable() . You can call it like ko.isObservable(vm[key]) . Update from comment: Here is a function to determine if something is a computed observable: UPDATE: If you are using KO 2.1+ - then you can use ko.isComputed directly.
Command Block. The Command Block is a redstone-powered block that was made available in the 1.4 update for Minecraft. The Command Block will perform server Commands when attached to a redstone circuit. This block cannot be crafted, and only server operators are allowed to place and use them.
World edit CUI is just an add on you need the original world edit for it to work. If you have that then the minecraft is probably not working because you have an outdated version of world edit/single player commands (1.3.1 minecraft and only 1.2.5 world edit/single player commands).