In the same way you can add commands to artyom, you can remove them. Use the emptyCommands method to remove all the commands loaded in artyom:
let artyom = new Artyom();
//Clear all the available commands of artyom
artyom.emptyCommands();
//Then retrieve
var commands = artyom.getAvailableCommands();
console.log(commands); // Ouputs : []