Identify the classes and associations in the following narrative and draw a class diagram with multiplicities: Barb maintains a real estate tracking system for Orange County. There are currently 34 incorporated cities and 15 unincorporated communities in the county. Barb tracks all of these as cities. Within each city, there is at least one and could be many neighborhoods. Within each neighborhood, there is at least one and likely many houses. For each house, Barb tracks information for all the sales in the last 20 years, although some houses have not been sold in the last 20 years.