Robot Realty is a US real estate firm that lists properties for sale in the US. The firm has a number of sales offices in several states. They assign each sales office an office ID, and they need to store the office's street address, state and zip code. Each sales office is assigned one or more employees. An employee can only be assigned to one sales office - if an employee changes offices over time, the database is updated accordingly and no history is kept. Robot needs to keep track of every employee's name (first and last) and all phone numbers where they can be reached. For each sales office, there is always one employee assigned to manage that office. The employee can only manage the office to which he or she is assigned. Robot lists properties for sale. Each property has a current owner (or owners) that wants to sell the property. Robot needs to keep track of what percentage of each property is owned by each owner. A property can only be listed by one office, although an office can list any number of properties. Robot does not need to track any information regarding the sale of the property or who buys it, just 149 the information listed above. For each owner, Robot needs to store the owner's name (first and last) and age. For each property, Robot needs to store the address (street, city, state, zip) and a listed price. Finally, Robot needs to create a report each month showing which employees work at each office, and the total value of the properties listed by the company. Draw an object model that shows the necessary data components of this system. If you make assumptions (which you should keep to an absolute minimum!), make sure to list them in detail