package com.michaelthomas.set; import java.util.HashSet; import java.util.Set; class MySet { //NOTE: For learning, you must see the JUnit test file in the /test/ directory and matching package! Set buildHashSetCarVendors1() { Set set = new HashSet(); set.add("BMW"); set.add("Ford"); set.add("Toyota"); return set; } Set buildHashSetCarVendors2() { Set set = new HashSet(); set.add("BMW"); set.add("Mercedes"); set.add("Chevorlet"); return set; } Set buildHashSetWithNulls() { Set set = new HashSet(); set.add("BMW"); set.add(null); return set; } }