Draw an E-R diagram for each of the following situations (if you believe that you need to make additional assumptions, clearly state them for each situation):2. A university has a large number of courses in its catalog. Attributes of COURSE include Course_Number (identifier), Course_Name, and Units. Each course may have one or more different courses as prerequisites, or may have no prerequisites. Similarly, a particular course may be a prerequisite for any number of courses, or may not be prerequisite for any other course. Provide a good definition of COURSE. Why is your definition a good one?