-import android.support.design.widget.FloatingActionButton;
-import android.support.design.widget.Snackbar;
-import android.support.v4.app.FragmentManager;
-import android.support.v4.app.NavUtils;
-import android.support.v7.app.ActionBar;
-import android.support.v7.app.AppCompatActivity;
-// `AppCompatDialogFragment` is required instead of `DialogFragment` or an error is produced on API <=22.
-import android.support.v7.app.AppCompatDialogFragment;
-import android.support.v7.widget.Toolbar;