@Override
public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
    Adapter adapter = new Adapter(cursor);
    adapter.setHasStableIds(true);
    mRecyclerView.setAdapter(adapter);

    GridLayoutManager gridLayoutManager =
            new GridLayoutManager(this, mColumnCount, GridLayoutManager.VERTICAL, false);

    mRecyclerView.setLayoutManager(gridLayoutManager);
}

@Override
public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
    Adapter adapter = new Adapter(cursor);
    adapter.setHasStableIds(true);
    mRecyclerView.setAdapter(adapter);

    GridLayoutManager gridLayoutManager =
            new GridLayoutManager(this, mColumnCount, GridLayoutManager.VERTICAL, false);

    mRecyclerView.setLayoutManager(gridLayoutManager);

    // Adding the custom ItemDecoration
    EqualOffsetItemDecoration itemDecoration = new EqualOffsetItemDecoration(this, R.dimen.card_view_margin, mColumnCount);
    mRecyclerView.addItemDecoration(itemDecoration);
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    ...

    mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    mColumnCount = getResources().getInteger(R.integer.list_column_count);

    /*
    In order to have equal spacing along the edges of the screen as well as between the
    child views of the RecyclerView, an EqualOffsetItemDecoration is applied to the RecyclerView.
     */
    EqualOffsetItemDecoration itemDecoration = new EqualOffsetItemDecoration(this, R.dimen.card_view_margin, mColumnCount);
    mRecyclerView.addItemDecoration(itemDecoration);

    ...
}