message: swapcommands function
diff: @@ -30,6 +30,11 @@ export default class TestCase {
  }
  }
  + @action swapCommands(from, to) {
  + const command = this.commands.splice(from, 1)[0];
  + this.insertCommandAt(command, to);
  + }
  +
  @action removeCommand(command) {
  this.commands.remove(command);
  }
  