@Override
 public void onResponse(String response) {
   searchUserAdapter.setIsSearchMode(true);
   tv_friends_list.setText(R.string.search_result_list);
   searchUserAdapter.clearData();
   user = JsonUtils.getListFromJson(response, User.class);
   searchUserAdapter.getList().addAll(user);
   searchUserAdapter.notifyDataSetChanged();
 }
 @Override
 public void onResponse(String response) {
   searchUserAdapter.setIsSearchMode(false);
   searchUserAdapter.clearData();
   JSONObject jsonObject;
   try {
     jsonObject = new JSONObject(response);
     String json = jsonObject.getString("users");
     user = JsonUtils.getListFromJson(json, User.class);
     mProgressBar.setVisibility(View.GONE);
     searchUserAdapter.getList().addAll(user);
     searchUserAdapter.notifyDataSetChanged();
   } catch (JSONException e) {
     e.printStackTrace();
   }
 }