This went a bit beyond the spec --- it makes sense to do this, but it wasn't required of you. 

Mostly, if I have a vehicle, I want to be able to update it.

```ruby
class Vehicle
  def update(args)
    @color = args.fetch(:color) if args[:color]
    @make = args.fetch(:make) if args[:make]
    @model = args.fetch(:model) if args[:model]
    @year = args.fetch(:year).to_s if args[:year]
    self
  end
end
```