java - How to solve "It is indirectly referenced from required .class files" error in android? -

i building android application using chat model. there website name quickblox server side part handle them. using application.they provide sample android code too, have import sample code , add lib , jar need run project.

now problem in 1 of class there error of "it indirectly referenced required .class files" dose mean , how solve can 1 me in solving issue.

below class code -

public class usersadapter extends baseadapter {  private list<qbuser> datasource; private layoutinflater inflater; private list<qbuser> selected = new arraylist<qbuser>();  public usersadapter(list<qbuser> datasource, context ctx) {     this.datasource = datasource;     this.inflater = layoutinflater.from(ctx); }  public list<qbuser> getselected() {     return selected; }  @override public int getcount() {     return datasource.size(); }  @override public object getitem(int position) {     return datasource.get(position); }  @override public long getitemid(int position) {     return position; }  @override public view getview(int position, view convertview, viewgroup parent) {     viewholder holder;     if (convertview == null) {         convertview = inflater.inflate(r.layout.list_item_user, null);         holder = new viewholder();         holder.login = (textview) convertview.findviewbyid(r.id.userlogin);         holder.add = (checkbox) convertview.findviewbyid(r.id.addcheckbox);         convertview.settag(holder);     } else {         holder = (viewholder) convertview.gettag();     }     final qbuser user = datasource.get(position);     if (user != null) {         holder.login.settext(user.getlogin());         holder.add.setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view v) {                 if ((((checkbox) v).ischecked())) {                     selected.add(user);                 } else {                     selected.remove(user);                 }             }         });         holder.add.setchecked(selected.contains(user));     }     return convertview; }  private static class viewholder {     textview login;     checkbox add; } 

}

this documentation code android - [http://quickblox.com/developers/android][1]