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.
Open the console again with T and type this command: /give (yourusername) minecraft:command_block 64. Instead of (yourusername), type in your full Minecraft username, without parentheses. 1  Your username is case sensitive. 2  If nothing happens, you may need to update minecraft to at least version 1.4.. Enter a command. You can enter just about any command in the command block's text field, then press Done to save it in the block. There's a long list of commands included below, but try summon Sheep for your first experiment.