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.
After that, save, run Minecraft once and quit the launcher. Get the latest version of forge for your Minecraft version and run the installer. The reason why it needs you to run Minecraft 1.7.2 is because it is adding classes to the 1.7.2.jar file and installing patches.