# File test/test_params.rb, line 1628
    def test_argument_number
      init_arguments
      assert_equal(0, @entry.args[3])
      @entry.set_arg_at(3, 9999)
      assert_equal(9999, @entry.args[3])
      @entry.set_arg_at(3, nil) # allowed
      assert_exception(RuntimeError) {
        @entry.set_arg_at(3, '9999') # not allowed
      }
    end