void (String[] args) { A a1 = new A(); assert a1.field == 0; A a2 = a1; assert <warning descr="Condition 'a2.field == 0' is always 'true'">a2.field == 0</warning>; a1.field = 10; assert <warning descr="Condition 'a2.field == 10' is always 'true'">a2.field == 10</warning>; }