class Wrench { public static void main(String [] args) { Wrench w = new Wrench(); Wrench w2 = new Wrench(); w2 = go(w,w2); System.out.print(w2 == w); } static Wrench go(Wrench wr1, Wrench wr2) { Wrench wr3 = wr1; wr1 = wr2; wr2 = wr3; return wr3; } } 结果是什么?()