Unable to get profile pic using twitter android kit

Question

Iam trying to get twitter profile pic by using Twitter android kit.I place this below code inside a button event but iam unable to retrive it success or failure anyone should excecuted but both qare not excecuting i debugged using break point and single step excecution the code does not excecute after the first line following the if statement.

final TwitterSession session = TwitterCore.getInstance().getSessionManager().getActiveSession();

    if(session!=null)
    {
        TwitterCore.getInstance().getApiClient().getAccountService().verifyCredentials(true, true, false).enqueue(new Callback<User>() {
            @Override
            public void success(Result<User> result) {
                  String imgurl = result.data.profileImageUrl;
            }

            @Override
            public void failure(TwitterException exception) {
                Toast.makeText(getActivity(),exception.toString(),Toast.LENGTH_LONG).show();

            }
        });