@NonNull
 public FileChooserDialog build() {
   FileChooserDialog dialog = new FileChooserDialog();
   Bundle args = new Bundle();
   args.putSerializable("builder", this);
   dialog.setArguments(args);
   return dialog;
 }
 @NonNull
 public FileChooserDialog show() {
   FileChooserDialog dialog = build();
   dialog.show(mContext);
   return dialog;
 }