tre

public static void main(String[] args){
    Contact tmp1 = new Contact();
    tmp1.setName("aac");
    Contact tmp2 = new Contact();
    tmp2.setName("abc");
    Contact tmp3 = new Contact();
    tmp3.setName("aab");
    Contact tmp4 = new Contact();
    tmp4.setName("qwe");
    
    ContactList testList = new ContactList();
    testList.add(tmp4);
    testList.add(tmp1);
    testList.add(tmp2);
    testList.add(tmp3);
    System.out.println(testList.getSortedCollection("a").toString());
}