1. Draw a Domain Model for a petrol station that sells different types of petrol along with other products. If you're not very used to using petrol stations you might like to visit one near you and watch what happens. You may even like to ask the people who work there some questions. You will need to make some careful decisions about what level of abstraction to represent, what conceptual classes are appropriate, and what associations should be recorded. Be sure to include multiplicities, and appropriate attributes. You will need to keep your model reasonably comprehensible, so be sure not to get too carried away modelling many different conceptual classes, but choose the ones that you do model carefully 2. Now, let's assume your petrol station is a self-service one (most are nowadays). Draw an interaction diagram (in the style presented in this week's lectures), with at least three participants (vertical life-lines), which shows the interactions that take place in a typical sale of unleaded fuel