classA{private String features;public String getFeatures(){return features;}publicvoidsetFeatures(String features){this.features = features;}}publicstaticvoidmain(String[] args){
A a = null;test(a);
System.out.println("main(),a="+a);//a=null}publicstaticvoidtest(A a){
A aa =newA();
aa.setFeatures("feature");
a = aa;}