# File test/test_params.rb, line 1663
    def test_argument_select
      init_arguments
      assert_equal('foo', @entry.args[6])
      @entry.set_arg_at(6, 'bar')
      assert_equal('bar', @entry.args[6])
      @entry.set_arg_at(6, 'foo') # allowed
      @entry.set_arg_at(6, 'bar') # allowed
      @entry.set_arg_at(6, 'baz') # allowed
      assert_exception(RuntimeError) {
        @entry.set_arg_at(6, 'quux') # not allowed
      }
      assert_exception(RuntimeError) {
        @entry.set_arg_at(6, nil) # not allowed
      }
    end