(Exercise 9.7 of [Priestley; 2004]) The code below shows a class DataSet, which provides basic statistical functionality on a set of data, and a class Marks, which uses DataSet to store and work out the average of a set of marks. The main function is shown reads in two marks and uses Marks to store them and print out the average. Draw a sequence diagram showing the interaction that takes place when the main function executes.

class DataSet { private float data[]; private int items; public DataSet() { data = new float[256]; items = 0; } public void addDataPoint(float d) { data[items++] = d; } public float mean() { float total = 0; for(int i 0; i