(1) move data loading from onCreateView() to onResume();
(2) update condition on onScroll() to prevent NoSuchElement exception;
(3) remove unnecessary imports;
add enum ButtonAction for identifying which button is pressed in the view of vehicle_index_row.xml;
implement Vehicle model on VehicleAdapter;
(1) implement Vehicle model on MarketplaceFragment;
(2) update onResume() and onGetRequestTaskResult() to download vehicles info for VehicleAdapter;
disable "swipe to load more" and "swipe to reload" features temporarily;
add VehicleIndexRowButtonActionHolder private class under VehicleAdapter;
implement VehicleIndexRowButtonActionHolder for Like button on VehicleAdapter;
implement OnClickListener on VehicleAdapter for Like button using VehicleIndexRowButtonActionHolder;