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.
Press Tab to see a list of block names. From here, you can find the block that you want to fill the area. If you know that its name starts with a certain couple of letters, type those letters, and then press Tab for a narrower search. After you see which block you want to use type it after the minecraft: .