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.
Unlike the Alpha, Beta and Minecraft 1.0 versions of Minecraft, you can not craft items or inflict damage. Much like Creative Mode, there are an infinite amount of blocks the player can use at their disposal, although, you can only place the old textured cobblestone.