A real estate firm keeps track of the houses for sale and customers looking to buy houses. A house for sale can be listed with this firm or with a different one. For your information, being listed" with a firm means that the house owner has a contract with an agent who works for that firm. Each house on the market has price, address, owner, and a list of features, such as the number of bedrooms, bathrooms, type of heating, appliances, size of garage, and similar things. This list can be different for different houses, and some features can be present in some houses but missing in others. Likewise, each customer who is interested in buying a house has preferences for features (the number of bedrooms, bathrooms, etc.). Apart from these preferences, customers specify the price range of houses they are interested in buying. Draw an E-R diagram for this application showing cardinality ratio, participation constraints, attributes as well as key attributes. Clearly state any assumptions that you make.