def execute(app, *args)
      self.call_command(:execute).execute_app_name(app).execute_app_arg(args.map(&:to_s).join(' '))
    end
def execute(app, *args)
      self.call_command(:execute).execute_app_name(app).execute_app_arg(args.map(&:to_s).join(' '))
    end
convenience method